2016-03-28 14:33:48

by Lyude Paul

[permalink] [raw]
Subject: [PATCH v4 RESEND 0/5] Move workarounds from intel_dp_dpcd_read_wake() into drm's DP helpers

Resending this because it looks like replying to my previous series of patches
causes patchwork to pick up patches from the original version of this and
try to apply them along with this one.

This series of patches takes all of the workarounds we used in
intel_dp_dpcd_read_wake() for working around misbehaving sinks into drm's DP
aux transaction helpers, so that they can be applied to all aux transactions
across each driver. While this patch series was intended to fix issues with the
ThinkPad T560 not bringing displays connected to it's dock back up properly
after suspend, this should fix a lot of other various DP issues by ensuring
that we retry transactions appropriately in every possible failure scenario.

Changes since v3
- Split the patch that moves the logic out of intel_dp_dpcd_read_wake() into
multiple patches for each workaround that we apply, so that bisecting this
change isn't difficult in the event that this breaks something

- Made sure that drm_dp_dpcd_read() only returns the error it encountered during
the first attempted aux transaction, since the error that following retries
encounter might be different from the original

Changes since v2
- Reworked the patch again to incorporate all of the behavior of
intel_dp_dpcd_read_wake() into drm_dp_dpcd_read() and drm_dp_dpcd_access()

Changes since v1
- Patch has been reworked to take the retry logic out of intel_dp_mst_resume()
and into drm_dp_dpcd_access(), based off a suggestion from Daniel Vetter

- Commit message is much longer and gives a better description of the
issue this was originally intended to workaround.

Lyude (5):
drm/dp_helper: Increase retry interval to 1000us
drm/dp_helper: Always wait before retrying native aux transactions
drm/dp_helper: Retry aux transactions on all errors
drm/dp_helper: Perform throw-away read before actual read in
drm_dp_dpcd_read()
drm/i915: Get rid of intel_dp_dpcd_read_wake()

drivers/gpu/drm/drm_dp_helper.c | 55 ++++++++++++++++------------
drivers/gpu/drm/i915/intel_dp.c | 79 ++++++++++++-----------------------------
2 files changed, 54 insertions(+), 80 deletions(-)

--
2.5.5


2016-03-28 14:33:55

by Lyude Paul

[permalink] [raw]
Subject: [PATCH v4 RESEND 3/5] drm/dp_helper: Retry aux transactions on all errors

This is part of a patch series to migrate all of the workarounds for
commonly seen behavior from bad sinks in intel_dp_dpcd_read_wake() to
drm's DP helper.

We cannot rely on sinks NACKing or deferring when they can't receive
transactions, nor can we rely on any other sort of consistent error to
know when we should stop retrying. As such, we need to just retry
unconditionally on errors. We also make sure here to return the error we
encountered during the first transaction, since it's possible that
retrying the transaction might return a different error then we had
originally.

This, along with the previous patch, work around a weird bug with the
ThinkPad T560's and it's dock. When resuming the laptop, it appears that
there's a short period of time where we're unable to complete any aux
transactions, as they all immediately timeout. The only machine I'm able
to reproduce this on is the T560 as other production Skylake models seem
to be fine. The period during which AUX transactions fail appears to be
around 22ms long. AFAIK, the dock for the T560 never actually turns off,
the only difference is that it's in SST mode at the start of the resume
process, so it's unclear as to why it would need so much time to come
back up.

There's been a discussion on this issue going on for a while on the
intel-gfx mailing list about this that has, in addition to including
developers from Intel, also had the correspondence of one of the
hardware engineers for Intel:

http://www.spinics.net/lists/intel-gfx/msg88831.html
http://www.spinics.net/lists/intel-gfx/msg88410.html

We've already looked into a couple of possible explanations for the
problem:

- Calling intel_dp_mst_resume() before right fix.
intel_runtime_pm_enable_interrupts(). This was the first fix I tried,
and while it worked it definitely wasn't the right fix. This worked
because DP aux transactions don't actually require interrupts to work:

static uint32_t
intel_dp_aux_wait_done(struct intel_dp *intel_dp, bool has_aux_irq)
{
struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
struct drm_device *dev = intel_dig_port->base.base.dev;
struct drm_i915_private *dev_priv = dev->dev_private;
i915_reg_t ch_ctl = intel_dp->aux_ch_ctl_reg;
uint32_t status;
bool done;

#define C (((status = I915_READ_NOTRACE(ch_ctl)) & DP_AUX_CH_CTL_SEND_BUSY) == 0)
if (has_aux_irq)
done = wait_event_timeout(dev_priv->gmbus_wait_queue, C,
msecs_to_jiffies_timeout(10));
else
done = wait_for_atomic(C, 10) == 0;
if (!done)
DRM_ERROR("dp aux hw did not signal timeout (has irq: %i)!\n",
has_aux_irq);
#undef C

return status;
}

When there's no interrupts enabled, we end up timing out on the
wait_event_timeout() call, which causes us to check the DP status
register once to see if the transaction was successful or not. Since
this adds a 10ms delay to each aux transaction, it ends up adding a
long enough delay to the resume process for aux transactions to become
functional again. This gave us the illusion that enabling interrupts
had something to do with making things work again, and put me on the
wrong track for a while.

- Interrupts occurring when we try to perform the aux transactions
required to put the dock back into MST mode. This isn't the problem,
as the only interrupts I've observed that come during this timeout
period are from the snd_hda_intel driver, and disabling that driver
doesn't appear to change the behavior at all.

- Skylake's PSR block causing issues by performing aux transactions
while we try to bring the dock out of MST mode. Disabling PSR through
i915's command line options doesn't seem to change the behavior
either, nor does preventing the DMC firmware from being loaded.

Since this investigation went on for about 2 weeks, we decided it would
be better for the time being to just workaround this issue by making
sure AUX transactions wait a short period of time before retrying.

Signed-off-by: Lyude <[email protected]>
---
drivers/gpu/drm/drm_dp_helper.c | 39 +++++++++++++++++++++------------------
1 file changed, 21 insertions(+), 18 deletions(-)

diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index 3b915e2..86656ca 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -178,8 +178,8 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request,
unsigned int offset, void *buffer, size_t size)
{
struct drm_dp_aux_msg msg;
- unsigned int retry;
- int err = 0;
+ unsigned int retry, native_reply;
+ int err = 0, ret = 0;

memset(&msg, 0, sizeof(msg));
msg.address = offset;
@@ -194,34 +194,37 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request,
* sufficient, bump to 32 which makes Dell 4k monitors happier.
*/
for (retry = 0; retry < 32; retry++) {
- if (err != 0 && err != -ETIMEDOUT) {
+ if (ret != 0 && ret != -ETIMEDOUT) {
usleep_range(AUX_RETRY_INTERVAL,
AUX_RETRY_INTERVAL + 100);
}

mutex_lock(&aux->hw_mutex);
- err = aux->transfer(aux, &msg);
+ ret = aux->transfer(aux, &msg);
mutex_unlock(&aux->hw_mutex);
- if (err < 0) {
- if (err == -EBUSY)
- continue;

- return err;
- }
-
- switch (msg.reply & DP_AUX_NATIVE_REPLY_MASK) {
- case DP_AUX_NATIVE_REPLY_ACK:
- if (err < size)
- return -EPROTO;
- return err;
+ if (ret > 0) {
+ native_reply = msg.reply & DP_AUX_NATIVE_REPLY_MASK;
+ if (native_reply == DP_AUX_NATIVE_REPLY_ACK) {
+ if (ret == size)
+ return ret;

- case DP_AUX_NATIVE_REPLY_NACK:
- return -EIO;
+ ret = -EPROTO;
+ } else
+ ret = -EIO;
}
+
+ /*
+ * We want the error we return to be the error we received on
+ * the first transaction, since we may get a different error the
+ * next time we retry
+ */
+ if (!err)
+ err = ret;
}

DRM_DEBUG_KMS("too many retries, giving up\n");
- return -EIO;
+ return err;
}

/**
--
2.5.5

2016-03-28 14:33:52

by Lyude Paul

[permalink] [raw]
Subject: [PATCH v4 RESEND 2/5] drm/dp_helper: Always wait before retrying native aux transactions

This is part of a patch series to migrate all of the workarounds for
commonly seen behavior from bad sinks in intel_dp_dpcd_read_wake() to
drm's DP helper.

Some sinks need some time during the process of resuming the system from
sleep before they're ready to handle transactions. While it would be
nice if they responded with NACKs in these scenarios, this isn't always
the case as a few sinks will just timeout on all of the transactions
they receive until they're ready.

Signed-off-by: Lyude <[email protected]>
---
drivers/gpu/drm/drm_dp_helper.c | 11 +++++------
1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index d1128fb..3b915e2 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -179,7 +179,7 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request,
{
struct drm_dp_aux_msg msg;
unsigned int retry;
- int err;
+ int err = 0;

memset(&msg, 0, sizeof(msg));
msg.address = offset;
@@ -194,6 +194,10 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request,
* sufficient, bump to 32 which makes Dell 4k monitors happier.
*/
for (retry = 0; retry < 32; retry++) {
+ if (err != 0 && err != -ETIMEDOUT) {
+ usleep_range(AUX_RETRY_INTERVAL,
+ AUX_RETRY_INTERVAL + 100);
+ }

mutex_lock(&aux->hw_mutex);
err = aux->transfer(aux, &msg);
@@ -205,7 +209,6 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request,
return err;
}

-
switch (msg.reply & DP_AUX_NATIVE_REPLY_MASK) {
case DP_AUX_NATIVE_REPLY_ACK:
if (err < size)
@@ -214,10 +217,6 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request,

case DP_AUX_NATIVE_REPLY_NACK:
return -EIO;
-
- case DP_AUX_NATIVE_REPLY_DEFER:
- usleep_range(AUX_RETRY_INTERVAL, AUX_RETRY_INTERVAL + 100);
- break;
}
}

--
2.5.5

2016-03-28 14:34:31

by Lyude Paul

[permalink] [raw]
Subject: [PATCH v4 RESEND 5/5] drm/i915: Get rid of intel_dp_dpcd_read_wake()

Since we've fixed up drm_dp_dpcd_read() to allow for retries when things
timeout, there's no use for having this function anymore. Good riddens.

Signed-off-by: Lyude <[email protected]>
---
drivers/gpu/drm/i915/intel_dp.c | 79 ++++++++++++-----------------------------
1 file changed, 22 insertions(+), 57 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index f069a82..43c2933 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -3184,47 +3184,14 @@ static void chv_dp_post_pll_disable(struct intel_encoder *encoder)
}

/*
- * Native read with retry for link status and receiver capability reads for
- * cases where the sink may still be asleep.
- *
- * Sinks are *supposed* to come up within 1ms from an off state, but we're also
- * supposed to retry 3 times per the spec.
- */
-static ssize_t
-intel_dp_dpcd_read_wake(struct drm_dp_aux *aux, unsigned int offset,
- void *buffer, size_t size)
-{
- ssize_t ret;
- int i;
-
- /*
- * Sometime we just get the same incorrect byte repeated
- * over the entire buffer. Doing just one throw away read
- * initially seems to "solve" it.
- */
- drm_dp_dpcd_read(aux, DP_DPCD_REV, buffer, 1);
-
- for (i = 0; i < 3; i++) {
- ret = drm_dp_dpcd_read(aux, offset, buffer, size);
- if (ret == size)
- return ret;
- msleep(1);
- }
-
- return ret;
-}
-
-/*
* Fetch AUX CH registers 0x202 - 0x207 which contain
* link status information
*/
bool
intel_dp_get_link_status(struct intel_dp *intel_dp, uint8_t link_status[DP_LINK_STATUS_SIZE])
{
- return intel_dp_dpcd_read_wake(&intel_dp->aux,
- DP_LANE0_1_STATUS,
- link_status,
- DP_LINK_STATUS_SIZE) == DP_LINK_STATUS_SIZE;
+ return drm_dp_dpcd_read(&intel_dp->aux, DP_LANE0_1_STATUS, link_status,
+ DP_LINK_STATUS_SIZE) == DP_LINK_STATUS_SIZE;
}

/* These are source-specific values. */
@@ -3859,8 +3826,8 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp)
struct drm_i915_private *dev_priv = dev->dev_private;
uint8_t rev;

- if (intel_dp_dpcd_read_wake(&intel_dp->aux, 0x000, intel_dp->dpcd,
- sizeof(intel_dp->dpcd)) < 0)
+ if (drm_dp_dpcd_read(&intel_dp->aux, 0x000, intel_dp->dpcd,
+ sizeof(intel_dp->dpcd)) < 0)
return false; /* aux transfer failed */

DRM_DEBUG_KMS("DPCD: %*ph\n", (int) sizeof(intel_dp->dpcd), intel_dp->dpcd);
@@ -3871,9 +3838,9 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp)
/* Check if the panel supports PSR */
memset(intel_dp->psr_dpcd, 0, sizeof(intel_dp->psr_dpcd));
if (is_edp(intel_dp)) {
- intel_dp_dpcd_read_wake(&intel_dp->aux, DP_PSR_SUPPORT,
- intel_dp->psr_dpcd,
- sizeof(intel_dp->psr_dpcd));
+ drm_dp_dpcd_read(&intel_dp->aux, DP_PSR_SUPPORT,
+ intel_dp->psr_dpcd,
+ sizeof(intel_dp->psr_dpcd));
if (intel_dp->psr_dpcd[0] & DP_PSR_IS_SUPPORTED) {
dev_priv->psr.sink_support = true;
DRM_DEBUG_KMS("Detected EDP PSR Panel.\n");
@@ -3884,9 +3851,9 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp)
uint8_t frame_sync_cap;

dev_priv->psr.sink_support = true;
- intel_dp_dpcd_read_wake(&intel_dp->aux,
- DP_SINK_DEVICE_AUX_FRAME_SYNC_CAP,
- &frame_sync_cap, 1);
+ drm_dp_dpcd_read(&intel_dp->aux,
+ DP_SINK_DEVICE_AUX_FRAME_SYNC_CAP,
+ &frame_sync_cap, 1);
dev_priv->psr.aux_frame_sync = frame_sync_cap ? true : false;
/* PSR2 needs frame sync as well */
dev_priv->psr.psr2_support = dev_priv->psr.aux_frame_sync;
@@ -3902,15 +3869,13 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp)
/* Intermediate frequency support */
if (is_edp(intel_dp) &&
(intel_dp->dpcd[DP_EDP_CONFIGURATION_CAP] & DP_DPCD_DISPLAY_CONTROL_CAPABLE) &&
- (intel_dp_dpcd_read_wake(&intel_dp->aux, DP_EDP_DPCD_REV, &rev, 1) == 1) &&
+ (drm_dp_dpcd_read(&intel_dp->aux, DP_EDP_DPCD_REV, &rev, 1) == 1) &&
(rev >= 0x03)) { /* eDp v1.4 or higher */
__le16 sink_rates[DP_MAX_SUPPORTED_RATES];
int i;

- intel_dp_dpcd_read_wake(&intel_dp->aux,
- DP_SUPPORTED_LINK_RATES,
- sink_rates,
- sizeof(sink_rates));
+ drm_dp_dpcd_read(&intel_dp->aux, DP_SUPPORTED_LINK_RATES,
+ sink_rates, sizeof(sink_rates));

for (i = 0; i < ARRAY_SIZE(sink_rates); i++) {
int val = le16_to_cpu(sink_rates[i]);
@@ -3933,9 +3898,9 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp)
if (intel_dp->dpcd[DP_DPCD_REV] == 0x10)
return true; /* no per-port downstream info */

- if (intel_dp_dpcd_read_wake(&intel_dp->aux, DP_DOWNSTREAM_PORT_0,
- intel_dp->downstream_ports,
- DP_MAX_DOWNSTREAM_PORTS) < 0)
+ if (drm_dp_dpcd_read(&intel_dp->aux, DP_DOWNSTREAM_PORT_0,
+ intel_dp->downstream_ports,
+ DP_MAX_DOWNSTREAM_PORTS) < 0)
return false; /* downstream port status fetch failed */

return true;
@@ -3949,11 +3914,11 @@ intel_dp_probe_oui(struct intel_dp *intel_dp)
if (!(intel_dp->dpcd[DP_DOWN_STREAM_PORT_COUNT] & DP_OUI_SUPPORT))
return;

- if (intel_dp_dpcd_read_wake(&intel_dp->aux, DP_SINK_OUI, buf, 3) == 3)
+ if (drm_dp_dpcd_read(&intel_dp->aux, DP_SINK_OUI, buf, 3) == 3)
DRM_DEBUG_KMS("Sink OUI: %02hx%02hx%02hx\n",
buf[0], buf[1], buf[2]);

- if (intel_dp_dpcd_read_wake(&intel_dp->aux, DP_BRANCH_OUI, buf, 3) == 3)
+ if (drm_dp_dpcd_read(&intel_dp->aux, DP_BRANCH_OUI, buf, 3) == 3)
DRM_DEBUG_KMS("Branch OUI: %02hx%02hx%02hx\n",
buf[0], buf[1], buf[2]);
}
@@ -3969,7 +3934,7 @@ intel_dp_probe_mst(struct intel_dp *intel_dp)
if (intel_dp->dpcd[DP_DPCD_REV] < 0x12)
return false;

- if (intel_dp_dpcd_read_wake(&intel_dp->aux, DP_MSTM_CAP, buf, 1)) {
+ if (drm_dp_dpcd_read(&intel_dp->aux, DP_MSTM_CAP, buf, 1)) {
if (buf[0] & DP_MST_CAP) {
DRM_DEBUG_KMS("Sink is MST capable\n");
intel_dp->is_mst = true;
@@ -4106,7 +4071,7 @@ stop:
static bool
intel_dp_get_sink_irq(struct intel_dp *intel_dp, u8 *sink_irq_vector)
{
- return intel_dp_dpcd_read_wake(&intel_dp->aux,
+ return drm_dp_dpcd_read(&intel_dp->aux,
DP_DEVICE_SERVICE_IRQ_VECTOR,
sink_irq_vector, 1) == 1;
}
@@ -4116,7 +4081,7 @@ intel_dp_get_sink_irq_esi(struct intel_dp *intel_dp, u8 *sink_irq_vector)
{
int ret;

- ret = intel_dp_dpcd_read_wake(&intel_dp->aux,
+ ret = drm_dp_dpcd_read(&intel_dp->aux,
DP_SINK_COUNT_ESI,
sink_irq_vector, 14);
if (ret != 14)
@@ -4377,7 +4342,7 @@ intel_dp_detect_dpcd(struct intel_dp *intel_dp)
intel_dp->downstream_ports[0] & DP_DS_PORT_HPD) {
uint8_t reg;

- if (intel_dp_dpcd_read_wake(&intel_dp->aux, DP_SINK_COUNT,
+ if (drm_dp_dpcd_read(&intel_dp->aux, DP_SINK_COUNT,
&reg, 1) < 0)
return connector_status_unknown;

--
2.5.5

2016-03-28 14:34:49

by Lyude Paul

[permalink] [raw]
Subject: [PATCH v4 RESEND 4/5] drm/dp_helper: Perform throw-away read before actual read in drm_dp_dpcd_read()

This is part of a patch series to migrate all of the workarounds for
commonly seen behavior from bad sinks in intel_dp_dpcd_read_wake() to drm's
DP helper.

Some sinks will just return garbage for the first aux tranaction they
receive when coming out of sleep mode, so we need to perform an additional
read before the actual read to workaround this.

Signed-off-by: Lyude <[email protected]>
---
drivers/gpu/drm/drm_dp_helper.c | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index 86656ca..702c78a 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -244,6 +244,13 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request,
ssize_t drm_dp_dpcd_read(struct drm_dp_aux *aux, unsigned int offset,
void *buffer, size_t size)
{
+ /*
+ * Sometimes we just get the same incorrect byte repeated over the
+ * entire buffer. Doing one throw away read initially seems to "solve"
+ * it.
+ */
+ drm_dp_dpcd_access(aux, DP_AUX_NATIVE_READ, DP_DPCD_REV, buffer, 1);
+
return drm_dp_dpcd_access(aux, DP_AUX_NATIVE_READ, offset, buffer,
size);
}
--
2.5.5

2016-03-28 14:35:09

by Lyude Paul

[permalink] [raw]
Subject: [PATCH v4 RESEND 1/5] drm/dp_helper: Increase retry interval to 1000us

This is part of a patch series to migrate all of the workarounds for
commonly seen behavior from bad sinks in intel_dp_dpcd_read_wake() to
drm's DP helper.

Signed-off-by: Lyude <[email protected]>
---
drivers/gpu/drm/drm_dp_helper.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index 7d58f59..d1128fb 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -160,7 +160,7 @@ int drm_dp_bw_code_to_link_rate(u8 link_bw)
}
EXPORT_SYMBOL(drm_dp_bw_code_to_link_rate);

-#define AUX_RETRY_INTERVAL 500 /* us */
+#define AUX_RETRY_INTERVAL 1000 /* us */

/**
* DOC: dp helpers
--
2.5.5

2016-03-29 08:27:35

by Daniel Vetter

[permalink] [raw]
Subject: Re: [PATCH v4 RESEND 1/5] drm/dp_helper: Increase retry interval to 1000us

On Mon, Mar 28, 2016 at 10:33:22AM -0400, Lyude wrote:
> This is part of a patch series to migrate all of the workarounds for
> commonly seen behavior from bad sinks in intel_dp_dpcd_read_wake() to
> drm's DP helper.
>
> Signed-off-by: Lyude <[email protected]>
> ---
> drivers/gpu/drm/drm_dp_helper.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
> index 7d58f59..d1128fb 100644
> --- a/drivers/gpu/drm/drm_dp_helper.c
> +++ b/drivers/gpu/drm/drm_dp_helper.c
> @@ -160,7 +160,7 @@ int drm_dp_bw_code_to_link_rate(u8 link_bw)
> }
> EXPORT_SYMBOL(drm_dp_bw_code_to_link_rate);
>
> -#define AUX_RETRY_INTERVAL 500 /* us */
> +#define AUX_RETRY_INTERVAL 1000 /* us */

Was this to adapt to the msleep(1) in the i915 function? If so it's kinda
wrong anyway, since an msleep(1) actually sleeps 1 jiffy, and on most
systems that's a lot more than 1 ms. If it all still works, I'd just drop
this patch here. I suspect that the magic is all in the more aggressive
retrying and the throwaway read, not in how long we actually wait.

On patches 2-5: Reviewed-by: Daniel Vetter <[email protected]>

>
> /**
> * DOC: dp helpers
> --
> 2.5.5
>
> _______________________________________________
> dri-devel mailing list
> [email protected]
> https://lists.freedesktop.org/mailman/listinfo/dri-devel

--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

2016-03-29 14:05:45

by Lyude Paul

[permalink] [raw]
Subject: Re: [PATCH v4 RESEND 1/5] drm/dp_helper: Increase retry interval to 1000us

Yep, the rest of the patchset works fine without this patch

On Tue, 2016-03-29 at 10:27 +0200, Daniel Vetter wrote:
> On Mon, Mar 28, 2016 at 10:33:22AM -0400, Lyude wrote:
> >
> > This is part of a patch series to migrate all of the workarounds for
> > commonly seen behavior from bad sinks in intel_dp_dpcd_read_wake() to
> > drm's DP helper.
> >
> > Signed-off-by: Lyude <[email protected]>
> > ---
> >  drivers/gpu/drm/drm_dp_helper.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/drm_dp_helper.c
> > b/drivers/gpu/drm/drm_dp_helper.c
> > index 7d58f59..d1128fb 100644
> > --- a/drivers/gpu/drm/drm_dp_helper.c
> > +++ b/drivers/gpu/drm/drm_dp_helper.c
> > @@ -160,7 +160,7 @@ int drm_dp_bw_code_to_link_rate(u8 link_bw)
> >  }
> >  EXPORT_SYMBOL(drm_dp_bw_code_to_link_rate);
> >  
> > -#define AUX_RETRY_INTERVAL 500 /* us */
> > +#define AUX_RETRY_INTERVAL 1000 /* us */
> Was this to adapt to the msleep(1) in the i915 function? If so it's kinda
> wrong anyway, since an msleep(1) actually sleeps 1 jiffy, and on most
> systems that's a lot more than 1 ms. If it all still works, I'd just drop
> this patch here. I suspect that the magic is all in the more aggressive
> retrying and the throwaway read, not in how long we actually wait.
>
> On patches 2-5: Reviewed-by: Daniel Vetter <[email protected]>
>
> >
> >  
> >  /**
> >   * DOC: dp helpers
> > -- 
> > 2.5.5
> >
> > _______________________________________________
> > dri-devel mailing list
> > [email protected]
> > https://lists.freedesktop.org/mailman/listinfo/dri-devel
--
Cheers,
Lyude

2016-03-29 20:43:30

by Lyude Paul

[permalink] [raw]
Subject: [PATCH v5 4/5] drm/dp_helper: Perform throw-away read before actual read in drm_dp_dpcd_read()

This is part of a patch series to migrate all of the workarounds for
commonly seen behavior from bad sinks in intel_dp_dpcd_read_wake() to drm's
DP helper.

Some sinks will just return garbage for the first aux tranaction they
receive when coming out of sleep mode, so we need to perform an additional
read before the actual read to workaround this.

Changes since v5
- If the throwaway read in drm_dp_dpcd_read() fails, return the error
from that instead of continuing. This follows the same logic we do in
drm_dp_dpcd_access() (e.g. the error from the first transaction may
differ from the errors that proceeding attempts might return).

Signed-off-by: Lyude <[email protected]>
---
drivers/gpu/drm/drm_dp_helper.c | 12 ++++++++++++
1 file changed, 12 insertions(+)

diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index 86656ca..daf261d 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -244,6 +244,18 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request,
ssize_t drm_dp_dpcd_read(struct drm_dp_aux *aux, unsigned int offset,
void *buffer, size_t size)
{
+ int ret;
+
+ /*
+ * Sometimes we just get the same incorrect byte repeated over the
+ * entire buffer. Doing one throw away read initially seems to "solve"
+ * it.
+ */
+ ret = drm_dp_dpcd_access(aux, DP_AUX_NATIVE_READ, DP_DPCD_REV, buffer,
+ 1);
+ if (ret != 1)
+ return ret;
+
return drm_dp_dpcd_access(aux, DP_AUX_NATIVE_READ, offset, buffer,
size);
}
--
2.5.5

2016-03-30 14:26:53

by Jani Nikula

[permalink] [raw]
Subject: Re: [PATCH v4 RESEND 5/5] drm/i915: Get rid of intel_dp_dpcd_read_wake()

On Mon, 28 Mar 2016, Lyude <[email protected]> wrote:
> Since we've fixed up drm_dp_dpcd_read() to allow for retries when things
> timeout, there's no use for having this function anymore. Good riddens.
>
> Signed-off-by: Lyude <[email protected]>
> ---
> drivers/gpu/drm/i915/intel_dp.c | 79 ++++++++++++-----------------------------
> 1 file changed, 22 insertions(+), 57 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> index f069a82..43c2933 100644
> --- a/drivers/gpu/drm/i915/intel_dp.c
> +++ b/drivers/gpu/drm/i915/intel_dp.c
> @@ -3184,47 +3184,14 @@ static void chv_dp_post_pll_disable(struct intel_encoder *encoder)
> }
>
> /*
> - * Native read with retry for link status and receiver capability reads for
> - * cases where the sink may still be asleep.
> - *
> - * Sinks are *supposed* to come up within 1ms from an off state, but we're also
> - * supposed to retry 3 times per the spec.
> - */
> -static ssize_t
> -intel_dp_dpcd_read_wake(struct drm_dp_aux *aux, unsigned int offset,
> - void *buffer, size_t size)
> -{
> - ssize_t ret;
> - int i;
> -
> - /*
> - * Sometime we just get the same incorrect byte repeated
> - * over the entire buffer. Doing just one throw away read
> - * initially seems to "solve" it.
> - */
> - drm_dp_dpcd_read(aux, DP_DPCD_REV, buffer, 1);

Ville, care to check this series (except patch 1) with your display to
see if it still works?

BR,
Jani.


> -
> - for (i = 0; i < 3; i++) {
> - ret = drm_dp_dpcd_read(aux, offset, buffer, size);
> - if (ret == size)
> - return ret;
> - msleep(1);
> - }
> -
> - return ret;
> -}
> -
> -/*
> * Fetch AUX CH registers 0x202 - 0x207 which contain
> * link status information
> */
> bool
> intel_dp_get_link_status(struct intel_dp *intel_dp, uint8_t link_status[DP_LINK_STATUS_SIZE])
> {
> - return intel_dp_dpcd_read_wake(&intel_dp->aux,
> - DP_LANE0_1_STATUS,
> - link_status,
> - DP_LINK_STATUS_SIZE) == DP_LINK_STATUS_SIZE;
> + return drm_dp_dpcd_read(&intel_dp->aux, DP_LANE0_1_STATUS, link_status,
> + DP_LINK_STATUS_SIZE) == DP_LINK_STATUS_SIZE;
> }
>
> /* These are source-specific values. */
> @@ -3859,8 +3826,8 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp)
> struct drm_i915_private *dev_priv = dev->dev_private;
> uint8_t rev;
>
> - if (intel_dp_dpcd_read_wake(&intel_dp->aux, 0x000, intel_dp->dpcd,
> - sizeof(intel_dp->dpcd)) < 0)
> + if (drm_dp_dpcd_read(&intel_dp->aux, 0x000, intel_dp->dpcd,
> + sizeof(intel_dp->dpcd)) < 0)
> return false; /* aux transfer failed */
>
> DRM_DEBUG_KMS("DPCD: %*ph\n", (int) sizeof(intel_dp->dpcd), intel_dp->dpcd);
> @@ -3871,9 +3838,9 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp)
> /* Check if the panel supports PSR */
> memset(intel_dp->psr_dpcd, 0, sizeof(intel_dp->psr_dpcd));
> if (is_edp(intel_dp)) {
> - intel_dp_dpcd_read_wake(&intel_dp->aux, DP_PSR_SUPPORT,
> - intel_dp->psr_dpcd,
> - sizeof(intel_dp->psr_dpcd));
> + drm_dp_dpcd_read(&intel_dp->aux, DP_PSR_SUPPORT,
> + intel_dp->psr_dpcd,
> + sizeof(intel_dp->psr_dpcd));
> if (intel_dp->psr_dpcd[0] & DP_PSR_IS_SUPPORTED) {
> dev_priv->psr.sink_support = true;
> DRM_DEBUG_KMS("Detected EDP PSR Panel.\n");
> @@ -3884,9 +3851,9 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp)
> uint8_t frame_sync_cap;
>
> dev_priv->psr.sink_support = true;
> - intel_dp_dpcd_read_wake(&intel_dp->aux,
> - DP_SINK_DEVICE_AUX_FRAME_SYNC_CAP,
> - &frame_sync_cap, 1);
> + drm_dp_dpcd_read(&intel_dp->aux,
> + DP_SINK_DEVICE_AUX_FRAME_SYNC_CAP,
> + &frame_sync_cap, 1);
> dev_priv->psr.aux_frame_sync = frame_sync_cap ? true : false;
> /* PSR2 needs frame sync as well */
> dev_priv->psr.psr2_support = dev_priv->psr.aux_frame_sync;
> @@ -3902,15 +3869,13 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp)
> /* Intermediate frequency support */
> if (is_edp(intel_dp) &&
> (intel_dp->dpcd[DP_EDP_CONFIGURATION_CAP] & DP_DPCD_DISPLAY_CONTROL_CAPABLE) &&
> - (intel_dp_dpcd_read_wake(&intel_dp->aux, DP_EDP_DPCD_REV, &rev, 1) == 1) &&
> + (drm_dp_dpcd_read(&intel_dp->aux, DP_EDP_DPCD_REV, &rev, 1) == 1) &&
> (rev >= 0x03)) { /* eDp v1.4 or higher */
> __le16 sink_rates[DP_MAX_SUPPORTED_RATES];
> int i;
>
> - intel_dp_dpcd_read_wake(&intel_dp->aux,
> - DP_SUPPORTED_LINK_RATES,
> - sink_rates,
> - sizeof(sink_rates));
> + drm_dp_dpcd_read(&intel_dp->aux, DP_SUPPORTED_LINK_RATES,
> + sink_rates, sizeof(sink_rates));
>
> for (i = 0; i < ARRAY_SIZE(sink_rates); i++) {
> int val = le16_to_cpu(sink_rates[i]);
> @@ -3933,9 +3898,9 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp)
> if (intel_dp->dpcd[DP_DPCD_REV] == 0x10)
> return true; /* no per-port downstream info */
>
> - if (intel_dp_dpcd_read_wake(&intel_dp->aux, DP_DOWNSTREAM_PORT_0,
> - intel_dp->downstream_ports,
> - DP_MAX_DOWNSTREAM_PORTS) < 0)
> + if (drm_dp_dpcd_read(&intel_dp->aux, DP_DOWNSTREAM_PORT_0,
> + intel_dp->downstream_ports,
> + DP_MAX_DOWNSTREAM_PORTS) < 0)
> return false; /* downstream port status fetch failed */
>
> return true;
> @@ -3949,11 +3914,11 @@ intel_dp_probe_oui(struct intel_dp *intel_dp)
> if (!(intel_dp->dpcd[DP_DOWN_STREAM_PORT_COUNT] & DP_OUI_SUPPORT))
> return;
>
> - if (intel_dp_dpcd_read_wake(&intel_dp->aux, DP_SINK_OUI, buf, 3) == 3)
> + if (drm_dp_dpcd_read(&intel_dp->aux, DP_SINK_OUI, buf, 3) == 3)
> DRM_DEBUG_KMS("Sink OUI: %02hx%02hx%02hx\n",
> buf[0], buf[1], buf[2]);
>
> - if (intel_dp_dpcd_read_wake(&intel_dp->aux, DP_BRANCH_OUI, buf, 3) == 3)
> + if (drm_dp_dpcd_read(&intel_dp->aux, DP_BRANCH_OUI, buf, 3) == 3)
> DRM_DEBUG_KMS("Branch OUI: %02hx%02hx%02hx\n",
> buf[0], buf[1], buf[2]);
> }
> @@ -3969,7 +3934,7 @@ intel_dp_probe_mst(struct intel_dp *intel_dp)
> if (intel_dp->dpcd[DP_DPCD_REV] < 0x12)
> return false;
>
> - if (intel_dp_dpcd_read_wake(&intel_dp->aux, DP_MSTM_CAP, buf, 1)) {
> + if (drm_dp_dpcd_read(&intel_dp->aux, DP_MSTM_CAP, buf, 1)) {
> if (buf[0] & DP_MST_CAP) {
> DRM_DEBUG_KMS("Sink is MST capable\n");
> intel_dp->is_mst = true;
> @@ -4106,7 +4071,7 @@ stop:
> static bool
> intel_dp_get_sink_irq(struct intel_dp *intel_dp, u8 *sink_irq_vector)
> {
> - return intel_dp_dpcd_read_wake(&intel_dp->aux,
> + return drm_dp_dpcd_read(&intel_dp->aux,
> DP_DEVICE_SERVICE_IRQ_VECTOR,
> sink_irq_vector, 1) == 1;
> }
> @@ -4116,7 +4081,7 @@ intel_dp_get_sink_irq_esi(struct intel_dp *intel_dp, u8 *sink_irq_vector)
> {
> int ret;
>
> - ret = intel_dp_dpcd_read_wake(&intel_dp->aux,
> + ret = drm_dp_dpcd_read(&intel_dp->aux,
> DP_SINK_COUNT_ESI,
> sink_irq_vector, 14);
> if (ret != 14)
> @@ -4377,7 +4342,7 @@ intel_dp_detect_dpcd(struct intel_dp *intel_dp)
> intel_dp->downstream_ports[0] & DP_DS_PORT_HPD) {
> uint8_t reg;
>
> - if (intel_dp_dpcd_read_wake(&intel_dp->aux, DP_SINK_COUNT,
> + if (drm_dp_dpcd_read(&intel_dp->aux, DP_SINK_COUNT,
> &reg, 1) < 0)
> return connector_status_unknown;

--
Jani Nikula, Intel Open Source Technology Center

2016-04-12 10:18:06

by Jani Nikula

[permalink] [raw]
Subject: Re: [PATCH v4 RESEND 0/5] Move workarounds from intel_dp_dpcd_read_wake() into drm's DP helpers

On Mon, 28 Mar 2016, Lyude <[email protected]> wrote:
> Resending this because it looks like replying to my previous series of patches
> causes patchwork to pick up patches from the original version of this and
> try to apply them along with this one.

Lyude, these don't seem to apply cleanly, please rebase and repost, and
we can pick them up once Ville confirms they don't break his display.

BR,
Jani.


--
Jani Nikula, Intel Open Source Technology Center

2016-04-12 15:59:56

by Lyude Paul

[permalink] [raw]
Subject: Re: [PATCH v4 RESEND 0/5] Move workarounds from intel_dp_dpcd_read_wake() into drm's DP helpers

Sounds good, I'll have the rebased versions posted in a bit

On Tue, 2016-04-12 at 13:17 +0300, Jani Nikula wrote:
> On Mon, 28 Mar 2016, Lyude <[email protected]> wrote:
> >
> > Resending this because it looks like replying to my previous series
> > of patches
> > causes patchwork to pick up patches from the original version of
> > this and
> > try to apply them along with this one.
> Lyude, these don't seem to apply cleanly, please rebase and repost,
> and
> we can pick them up once Ville confirms they don't break his display.
>
> BR,
> Jani.
>
>
--
Cheers,
Lyude

2016-04-13 14:59:12

by Lyude Paul

[permalink] [raw]
Subject: [PATCH v5 1/4] drm/dp_helper: Always wait before retrying native aux transactions

This is part of a patch series to migrate all of the workarounds for
commonly seen behavior from bad sinks in intel_dp_dpcd_read_wake() to
drm's DP helper.

Some sinks need some time during the process of resuming the system from
sleep before they're ready to handle transactions. While it would be
nice if they responded with NACKs in these scenarios, this isn't always
the case as a few sinks will just timeout on all of the transactions
they receive until they're ready.

Signed-off-by: Lyude <[email protected]>
---
drivers/gpu/drm/drm_dp_helper.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index df64ed1..7dd330a 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -196,6 +196,10 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request,
* sufficient, bump to 32 which makes Dell 4k monitors happier.
*/
for (retry = 0; retry < 32; retry++) {
+ if (err != 0 && err != -ETIMEDOUT) {
+ usleep_range(AUX_RETRY_INTERVAL,
+ AUX_RETRY_INTERVAL + 100);
+ }

err = aux->transfer(aux, &msg);
if (err < 0) {
@@ -205,7 +209,6 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request,
goto unlock;
}

-
switch (msg.reply & DP_AUX_NATIVE_REPLY_MASK) {
case DP_AUX_NATIVE_REPLY_ACK:
if (err < size)
@@ -215,10 +218,6 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request,
case DP_AUX_NATIVE_REPLY_NACK:
err = -EIO;
goto unlock;
-
- case DP_AUX_NATIVE_REPLY_DEFER:
- usleep_range(AUX_RETRY_INTERVAL, AUX_RETRY_INTERVAL + 100);
- break;
}
}

--
2.5.5

2016-04-13 14:59:21

by Lyude Paul

[permalink] [raw]
Subject: [PATCH v5 4/4] drm/i915: Get rid of intel_dp_dpcd_read_wake()

Since we've fixed up drm_dp_dpcd_read() to allow for retries when things
timeout, there's no use for having this function anymore. Good riddens.

Signed-off-by: Lyude <[email protected]>
---
drivers/gpu/drm/i915/intel_dp.c | 81 ++++++++++++-----------------------------
1 file changed, 23 insertions(+), 58 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 6c6f95a2..363629c 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -3074,47 +3074,14 @@ static void chv_dp_post_pll_disable(struct intel_encoder *encoder)
}

/*
- * Native read with retry for link status and receiver capability reads for
- * cases where the sink may still be asleep.
- *
- * Sinks are *supposed* to come up within 1ms from an off state, but we're also
- * supposed to retry 3 times per the spec.
- */
-static ssize_t
-intel_dp_dpcd_read_wake(struct drm_dp_aux *aux, unsigned int offset,
- void *buffer, size_t size)
-{
- ssize_t ret;
- int i;
-
- /*
- * Sometime we just get the same incorrect byte repeated
- * over the entire buffer. Doing just one throw away read
- * initially seems to "solve" it.
- */
- drm_dp_dpcd_read(aux, DP_DPCD_REV, buffer, 1);
-
- for (i = 0; i < 3; i++) {
- ret = drm_dp_dpcd_read(aux, offset, buffer, size);
- if (ret == size)
- return ret;
- msleep(1);
- }
-
- return ret;
-}
-
-/*
* Fetch AUX CH registers 0x202 - 0x207 which contain
* link status information
*/
bool
intel_dp_get_link_status(struct intel_dp *intel_dp, uint8_t link_status[DP_LINK_STATUS_SIZE])
{
- return intel_dp_dpcd_read_wake(&intel_dp->aux,
- DP_LANE0_1_STATUS,
- link_status,
- DP_LINK_STATUS_SIZE) == DP_LINK_STATUS_SIZE;
+ return drm_dp_dpcd_read(&intel_dp->aux, DP_LANE0_1_STATUS, link_status,
+ DP_LINK_STATUS_SIZE) == DP_LINK_STATUS_SIZE;
}

/* These are source-specific values. */
@@ -3749,8 +3716,8 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp)
struct drm_i915_private *dev_priv = dev->dev_private;
uint8_t rev;

- if (intel_dp_dpcd_read_wake(&intel_dp->aux, 0x000, intel_dp->dpcd,
- sizeof(intel_dp->dpcd)) < 0)
+ if (drm_dp_dpcd_read(&intel_dp->aux, 0x000, intel_dp->dpcd,
+ sizeof(intel_dp->dpcd)) < 0)
return false; /* aux transfer failed */

DRM_DEBUG_KMS("DPCD: %*ph\n", (int) sizeof(intel_dp->dpcd), intel_dp->dpcd);
@@ -3758,8 +3725,8 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp)
if (intel_dp->dpcd[DP_DPCD_REV] == 0)
return false; /* DPCD not present */

- if (intel_dp_dpcd_read_wake(&intel_dp->aux, DP_SINK_COUNT,
- &intel_dp->sink_count, 1) < 0)
+ if (drm_dp_dpcd_read(&intel_dp->aux, DP_SINK_COUNT,
+ &intel_dp->sink_count, 1) < 0)
return false;

/*
@@ -3782,9 +3749,9 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp)
/* Check if the panel supports PSR */
memset(intel_dp->psr_dpcd, 0, sizeof(intel_dp->psr_dpcd));
if (is_edp(intel_dp)) {
- intel_dp_dpcd_read_wake(&intel_dp->aux, DP_PSR_SUPPORT,
- intel_dp->psr_dpcd,
- sizeof(intel_dp->psr_dpcd));
+ drm_dp_dpcd_read(&intel_dp->aux, DP_PSR_SUPPORT,
+ intel_dp->psr_dpcd,
+ sizeof(intel_dp->psr_dpcd));
if (intel_dp->psr_dpcd[0] & DP_PSR_IS_SUPPORTED) {
dev_priv->psr.sink_support = true;
DRM_DEBUG_KMS("Detected EDP PSR Panel.\n");
@@ -3795,9 +3762,9 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp)
uint8_t frame_sync_cap;

dev_priv->psr.sink_support = true;
- intel_dp_dpcd_read_wake(&intel_dp->aux,
- DP_SINK_DEVICE_AUX_FRAME_SYNC_CAP,
- &frame_sync_cap, 1);
+ drm_dp_dpcd_read(&intel_dp->aux,
+ DP_SINK_DEVICE_AUX_FRAME_SYNC_CAP,
+ &frame_sync_cap, 1);
dev_priv->psr.aux_frame_sync = frame_sync_cap ? true : false;
/* PSR2 needs frame sync as well */
dev_priv->psr.psr2_support = dev_priv->psr.aux_frame_sync;
@@ -3813,15 +3780,13 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp)
/* Intermediate frequency support */
if (is_edp(intel_dp) &&
(intel_dp->dpcd[DP_EDP_CONFIGURATION_CAP] & DP_DPCD_DISPLAY_CONTROL_CAPABLE) &&
- (intel_dp_dpcd_read_wake(&intel_dp->aux, DP_EDP_DPCD_REV, &rev, 1) == 1) &&
+ (drm_dp_dpcd_read(&intel_dp->aux, DP_EDP_DPCD_REV, &rev, 1) == 1) &&
(rev >= 0x03)) { /* eDp v1.4 or higher */
__le16 sink_rates[DP_MAX_SUPPORTED_RATES];
int i;

- intel_dp_dpcd_read_wake(&intel_dp->aux,
- DP_SUPPORTED_LINK_RATES,
- sink_rates,
- sizeof(sink_rates));
+ drm_dp_dpcd_read(&intel_dp->aux, DP_SUPPORTED_LINK_RATES,
+ sink_rates, sizeof(sink_rates));

for (i = 0; i < ARRAY_SIZE(sink_rates); i++) {
int val = le16_to_cpu(sink_rates[i]);
@@ -3844,9 +3809,9 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp)
if (intel_dp->dpcd[DP_DPCD_REV] == 0x10)
return true; /* no per-port downstream info */

- if (intel_dp_dpcd_read_wake(&intel_dp->aux, DP_DOWNSTREAM_PORT_0,
- intel_dp->downstream_ports,
- DP_MAX_DOWNSTREAM_PORTS) < 0)
+ if (drm_dp_dpcd_read(&intel_dp->aux, DP_DOWNSTREAM_PORT_0,
+ intel_dp->downstream_ports,
+ DP_MAX_DOWNSTREAM_PORTS) < 0)
return false; /* downstream port status fetch failed */

return true;
@@ -3860,11 +3825,11 @@ intel_dp_probe_oui(struct intel_dp *intel_dp)
if (!(intel_dp->dpcd[DP_DOWN_STREAM_PORT_COUNT] & DP_OUI_SUPPORT))
return;

- if (intel_dp_dpcd_read_wake(&intel_dp->aux, DP_SINK_OUI, buf, 3) == 3)
+ if (drm_dp_dpcd_read(&intel_dp->aux, DP_SINK_OUI, buf, 3) == 3)
DRM_DEBUG_KMS("Sink OUI: %02hx%02hx%02hx\n",
buf[0], buf[1], buf[2]);

- if (intel_dp_dpcd_read_wake(&intel_dp->aux, DP_BRANCH_OUI, buf, 3) == 3)
+ if (drm_dp_dpcd_read(&intel_dp->aux, DP_BRANCH_OUI, buf, 3) == 3)
DRM_DEBUG_KMS("Branch OUI: %02hx%02hx%02hx\n",
buf[0], buf[1], buf[2]);
}
@@ -3883,7 +3848,7 @@ intel_dp_probe_mst(struct intel_dp *intel_dp)
if (intel_dp->dpcd[DP_DPCD_REV] < 0x12)
return false;

- if (intel_dp_dpcd_read_wake(&intel_dp->aux, DP_MSTM_CAP, buf, 1)) {
+ if (drm_dp_dpcd_read(&intel_dp->aux, DP_MSTM_CAP, buf, 1)) {
if (buf[0] & DP_MST_CAP) {
DRM_DEBUG_KMS("Sink is MST capable\n");
intel_dp->is_mst = true;
@@ -4020,7 +3985,7 @@ stop:
static bool
intel_dp_get_sink_irq(struct intel_dp *intel_dp, u8 *sink_irq_vector)
{
- return intel_dp_dpcd_read_wake(&intel_dp->aux,
+ return drm_dp_dpcd_read(&intel_dp->aux,
DP_DEVICE_SERVICE_IRQ_VECTOR,
sink_irq_vector, 1) == 1;
}
@@ -4030,7 +3995,7 @@ intel_dp_get_sink_irq_esi(struct intel_dp *intel_dp, u8 *sink_irq_vector)
{
int ret;

- ret = intel_dp_dpcd_read_wake(&intel_dp->aux,
+ ret = drm_dp_dpcd_read(&intel_dp->aux,
DP_SINK_COUNT_ESI,
sink_irq_vector, 14);
if (ret != 14)
--
2.5.5

2016-04-13 14:59:10

by Lyude Paul

[permalink] [raw]
Subject: [PATCH v5 0/4] Move workarounds from intel_dp_dpcd_read_wake() into drm's DP helpers

Rebased the patches to apply against drm-intel-nightly

Lyude (4):
drm/dp_helper: Always wait before retrying native aux transactions
drm/dp_helper: Retry aux transactions on all errors
drm/dp_helper: Perform throw-away read before actual read in
drm_dp_dpcd_read()
drm/i915: Get rid of intel_dp_dpcd_read_wake()

drivers/gpu/drm/drm_dp_helper.c | 59 ++++++++++++++++++------------
drivers/gpu/drm/i915/intel_dp.c | 81 ++++++++++++-----------------------------
2 files changed, 59 insertions(+), 81 deletions(-)

--
2.5.5

2016-04-13 14:59:36

by Lyude Paul

[permalink] [raw]
Subject: [PATCH v5 3/4] drm/dp_helper: Perform throw-away read before actual read in drm_dp_dpcd_read()

This is part of a patch series to migrate all of the workarounds for
commonly seen behavior from bad sinks in intel_dp_dpcd_read_wake() to drm's
DP helper.

Some sinks will just return garbage for the first aux tranaction they
receive when coming out of sleep mode, so we need to perform an additional
read before the actual read to workaround this.

Changes since v5
- If the throwaway read in drm_dp_dpcd_read() fails, return the error
from that instead of continuing. This follows the same logic we do in
drm_dp_dpcd_access() (e.g. the error from the first transaction may
differ from the errors that proceeding attempts might return).

Signed-off-by: Lyude <[email protected]>
---
drivers/gpu/drm/drm_dp_helper.c | 12 ++++++++++++
1 file changed, 12 insertions(+)

diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index 540c3e4..aa80702 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -248,6 +248,18 @@ unlock:
ssize_t drm_dp_dpcd_read(struct drm_dp_aux *aux, unsigned int offset,
void *buffer, size_t size)
{
+ int ret;
+
+ /*
+ * Sometimes we just get the same incorrect byte repeated over the
+ * entire buffer. Doing one throw away read initially seems to "solve"
+ * it.
+ */
+ ret = drm_dp_dpcd_access(aux, DP_AUX_NATIVE_READ, DP_DPCD_REV, buffer,
+ 1);
+ if (ret != 1)
+ return ret;
+
return drm_dp_dpcd_access(aux, DP_AUX_NATIVE_READ, offset, buffer,
size);
}
--
2.5.5

2016-04-13 14:59:56

by Lyude Paul

[permalink] [raw]
Subject: [PATCH v5 2/4] drm/dp_helper: Retry aux transactions on all errors

This is part of a patch series to migrate all of the workarounds for
commonly seen behavior from bad sinks in intel_dp_dpcd_read_wake() to
drm's DP helper.

We cannot rely on sinks NACKing or deferring when they can't receive
transactions, nor can we rely on any other sort of consistent error to
know when we should stop retrying. As such, we need to just retry
unconditionally on errors. We also make sure here to return the error we
encountered during the first transaction, since it's possible that
retrying the transaction might return a different error then we had
originally.

This, along with the previous patch, work around a weird bug with the
ThinkPad T560's and it's dock. When resuming the laptop, it appears that
there's a short period of time where we're unable to complete any aux
transactions, as they all immediately timeout. The only machine I'm able
to reproduce this on is the T560 as other production Skylake models seem
to be fine. The period during which AUX transactions fail appears to be
around 22ms long. AFAIK, the dock for the T560 never actually turns off,
the only difference is that it's in SST mode at the start of the resume
process, so it's unclear as to why it would need so much time to come
back up.

There's been a discussion on this issue going on for a while on the
intel-gfx mailing list about this that has, in addition to including
developers from Intel, also had the correspondence of one of the
hardware engineers for Intel:

http://www.spinics.net/lists/intel-gfx/msg88831.html
http://www.spinics.net/lists/intel-gfx/msg88410.html

We've already looked into a couple of possible explanations for the
problem:

- Calling intel_dp_mst_resume() before right fix.
intel_runtime_pm_enable_interrupts(). This was the first fix I tried,
and while it worked it definitely wasn't the right fix. This worked
because DP aux transactions don't actually require interrupts to work:

static uint32_t
intel_dp_aux_wait_done(struct intel_dp *intel_dp, bool has_aux_irq)
{
struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
struct drm_device *dev = intel_dig_port->base.base.dev;
struct drm_i915_private *dev_priv = dev->dev_private;
i915_reg_t ch_ctl = intel_dp->aux_ch_ctl_reg;
uint32_t status;
bool done;

#define C (((status = I915_READ_NOTRACE(ch_ctl)) & DP_AUX_CH_CTL_SEND_BUSY) == 0)
if (has_aux_irq)
done = wait_event_timeout(dev_priv->gmbus_wait_queue, C,
msecs_to_jiffies_timeout(10));
else
done = wait_for_atomic(C, 10) == 0;
if (!done)
DRM_ERROR("dp aux hw did not signal timeout (has irq: %i)!\n",
has_aux_irq);
#undef C

return status;
}

When there's no interrupts enabled, we end up timing out on the
wait_event_timeout() call, which causes us to check the DP status
register once to see if the transaction was successful or not. Since
this adds a 10ms delay to each aux transaction, it ends up adding a
long enough delay to the resume process for aux transactions to become
functional again. This gave us the illusion that enabling interrupts
had something to do with making things work again, and put me on the
wrong track for a while.

- Interrupts occurring when we try to perform the aux transactions
required to put the dock back into MST mode. This isn't the problem,
as the only interrupts I've observed that come during this timeout
period are from the snd_hda_intel driver, and disabling that driver
doesn't appear to change the behavior at all.

- Skylake's PSR block causing issues by performing aux transactions
while we try to bring the dock out of MST mode. Disabling PSR through
i915's command line options doesn't seem to change the behavior
either, nor does preventing the DMC firmware from being loaded.

Since this investigation went on for about 2 weeks, we decided it would
be better for the time being to just workaround this issue by making
sure AUX transactions wait a short period of time before retrying.

Signed-off-by: Lyude <[email protected]>
---
drivers/gpu/drm/drm_dp_helper.c | 42 +++++++++++++++++++++--------------------
1 file changed, 22 insertions(+), 20 deletions(-)

diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index 7dd330a..540c3e4 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -178,8 +178,8 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request,
unsigned int offset, void *buffer, size_t size)
{
struct drm_dp_aux_msg msg;
- unsigned int retry;
- int err = 0;
+ unsigned int retry, native_reply;
+ int err = 0, ret = 0;

memset(&msg, 0, sizeof(msg));
msg.address = offset;
@@ -196,37 +196,39 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request,
* sufficient, bump to 32 which makes Dell 4k monitors happier.
*/
for (retry = 0; retry < 32; retry++) {
- if (err != 0 && err != -ETIMEDOUT) {
+ if (ret != 0 && ret != -ETIMEDOUT) {
usleep_range(AUX_RETRY_INTERVAL,
AUX_RETRY_INTERVAL + 100);
}

- err = aux->transfer(aux, &msg);
- if (err < 0) {
- if (err == -EBUSY)
- continue;
-
- goto unlock;
- }
+ ret = aux->transfer(aux, &msg);

- switch (msg.reply & DP_AUX_NATIVE_REPLY_MASK) {
- case DP_AUX_NATIVE_REPLY_ACK:
- if (err < size)
- err = -EPROTO;
- goto unlock;
+ if (ret > 0) {
+ native_reply = msg.reply & DP_AUX_NATIVE_REPLY_MASK;
+ if (native_reply == DP_AUX_NATIVE_REPLY_ACK) {
+ if (ret == size)
+ goto unlock;

- case DP_AUX_NATIVE_REPLY_NACK:
- err = -EIO;
- goto unlock;
+ ret = -EPROTO;
+ } else
+ ret = -EIO;
}
+
+ /*
+ * We want the error we return to be the error we received on
+ * the first transaction, since we may get a different error the
+ * next time we retry
+ */
+ if (!err)
+ err = ret;
}

DRM_DEBUG_KMS("too many retries, giving up\n");
- err = -EIO;
+ ret = err;

unlock:
mutex_unlock(&aux->hw_mutex);
- return err;
+ return ret;
}

/**
--
2.5.5

2016-04-14 17:01:50

by Ville Syrjälä

[permalink] [raw]
Subject: Re: [PATCH v5 3/4] drm/dp_helper: Perform throw-away read before actual read in drm_dp_dpcd_read()

On Wed, Apr 13, 2016 at 10:58:32AM -0400, Lyude wrote:
> This is part of a patch series to migrate all of the workarounds for
> commonly seen behavior from bad sinks in intel_dp_dpcd_read_wake() to drm's
> DP helper.
>
> Some sinks will just return garbage for the first aux tranaction they
> receive when coming out of sleep mode, so we need to perform an additional
> read before the actual read to workaround this.
>
> Changes since v5
> - If the throwaway read in drm_dp_dpcd_read() fails, return the error
> from that instead of continuing. This follows the same logic we do in
> drm_dp_dpcd_access() (e.g. the error from the first transaction may
> differ from the errors that proceeding attempts might return).
>
> Signed-off-by: Lyude <[email protected]>
> ---
> drivers/gpu/drm/drm_dp_helper.c | 12 ++++++++++++
> 1 file changed, 12 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
> index 540c3e4..aa80702 100644
> --- a/drivers/gpu/drm/drm_dp_helper.c
> +++ b/drivers/gpu/drm/drm_dp_helper.c
> @@ -248,6 +248,18 @@ unlock:
> ssize_t drm_dp_dpcd_read(struct drm_dp_aux *aux, unsigned int offset,
> void *buffer, size_t size)
> {
> + int ret;
> +
> + /*
> + * Sometimes we just get the same incorrect byte repeated over the
> + * entire buffer. Doing one throw away read initially seems to "solve"
> + * it.
> + */

We might want to improve the comment a bit, now that I analyzed the
problem in more detail. So perhaps something like:

/*
* HP ZR24w corrupts the first DPCD access after entering power save
* mode. Eg. on a read, the entire buffer will be filled with the same
* byte. Do a throw away read to avoid corrupting anything we care
* about. Afterwards things will work correctly until the monitor
* gets woken up and subsequently re-enters power save mode.
*
* The user pressing any button on the monitor is enough to wake it
* up, so there is no particularly good place to do the workaround.
* We just have to do it before any DPCD access and hope that the
* monitor doesn't power down exactly after the throw away read.
*/

I'm thinking we should probably also do it for writes, since those
seem to be affected as well.

> + ret = drm_dp_dpcd_access(aux, DP_AUX_NATIVE_READ, DP_DPCD_REV, buffer,
> + 1);
> + if (ret != 1)
> + return ret;
> +
> return drm_dp_dpcd_access(aux, DP_AUX_NATIVE_READ, offset, buffer,
> size);
> }
> --
> 2.5.5

--
Ville Syrj?l?
Intel OTC

2016-04-15 14:26:20

by Lyude Paul

[permalink] [raw]
Subject: [PATCH v6 3/4] drm/dp_helper: Perform throw-away read before actual read in drm_dp_dpcd_read()

This is part of a patch series to migrate all of the workarounds for
commonly seen behavior from bad sinks in intel_dp_dpcd_read_wake() to drm's
DP helper.

Some sinks will just return garbage for the first aux tranaction they
receive when coming out of sleep mode, so we need to perform an additional
read before the actual read to workaround this.

Changes since v5
- If the throwaway read in drm_dp_dpcd_read() fails, return the error
from that instead of continuing. This follows the same logic we do in
drm_dp_dpcd_access() (e.g. the error from the first transaction may
differ from the errors that proceeding attempts might return).

Signed-off-by: Lyude <[email protected]>
---
drivers/gpu/drm/drm_dp_helper.c | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)

diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index 540c3e4..eeaf5a7 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -248,6 +248,25 @@ unlock:
ssize_t drm_dp_dpcd_read(struct drm_dp_aux *aux, unsigned int offset,
void *buffer, size_t size)
{
+ int ret;
+
+ /*
+ * HP ZR24w corrupts the first DPCD access after entering power save
+ * mode. Eg. on a read, the entire buffer will be filled with the same
+ * byte. Do a throw away read to avoid corrupting anything we care
+ * about. Afterwards things will work correctly until the monitor
+ * gets woken up and subsequently re-enters power save mode.
+ *
+ * The user pressing any button on the monitor is enough to wake it
+ * up, so there is no particularly good place to do the workaround.
+ * We just have to do it before any DPCD access and hope that the
+ * monitor doesn't power down exactly after the throw away read.
+ */
+ ret = drm_dp_dpcd_access(aux, DP_AUX_NATIVE_READ, DP_DPCD_REV, buffer,
+ 1);
+ if (ret != 1)
+ return ret;
+
return drm_dp_dpcd_access(aux, DP_AUX_NATIVE_READ, offset, buffer,
size);
}
--
2.5.5

2016-04-15 14:31:26

by Ville Syrjälä

[permalink] [raw]
Subject: Re: [PATCH v6 3/4] drm/dp_helper: Perform throw-away read before actual read in drm_dp_dpcd_read()

On Fri, Apr 15, 2016 at 10:25:35AM -0400, Lyude wrote:
> This is part of a patch series to migrate all of the workarounds for
> commonly seen behavior from bad sinks in intel_dp_dpcd_read_wake() to drm's
> DP helper.
>
> Some sinks will just return garbage for the first aux tranaction they
> receive when coming out of sleep mode, so we need to perform an additional
> read before the actual read to workaround this.
>
> Changes since v5
> - If the throwaway read in drm_dp_dpcd_read() fails, return the error
> from that instead of continuing. This follows the same logic we do in
> drm_dp_dpcd_access() (e.g. the error from the first transaction may
> differ from the errors that proceeding attempts might return).
>
> Signed-off-by: Lyude <[email protected]>

Reviewed-by: Ville Syrj?l? <[email protected]>
Tested-by: Ville Syrj?l? <[email protected]>

> ---
> drivers/gpu/drm/drm_dp_helper.c | 19 +++++++++++++++++++
> 1 file changed, 19 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
> index 540c3e4..eeaf5a7 100644
> --- a/drivers/gpu/drm/drm_dp_helper.c
> +++ b/drivers/gpu/drm/drm_dp_helper.c
> @@ -248,6 +248,25 @@ unlock:
> ssize_t drm_dp_dpcd_read(struct drm_dp_aux *aux, unsigned int offset,
> void *buffer, size_t size)
> {
> + int ret;
> +
> + /*
> + * HP ZR24w corrupts the first DPCD access after entering power save
> + * mode. Eg. on a read, the entire buffer will be filled with the same
> + * byte. Do a throw away read to avoid corrupting anything we care
> + * about. Afterwards things will work correctly until the monitor
> + * gets woken up and subsequently re-enters power save mode.
> + *
> + * The user pressing any button on the monitor is enough to wake it
> + * up, so there is no particularly good place to do the workaround.
> + * We just have to do it before any DPCD access and hope that the
> + * monitor doesn't power down exactly after the throw away read.
> + */
> + ret = drm_dp_dpcd_access(aux, DP_AUX_NATIVE_READ, DP_DPCD_REV, buffer,
> + 1);
> + if (ret != 1)
> + return ret;
> +
> return drm_dp_dpcd_access(aux, DP_AUX_NATIVE_READ, offset, buffer,
> size);
> }
> --
> 2.5.5

--
Ville Syrj?l?
Intel OTC

2016-04-22 16:54:13

by Daniel Vetter

[permalink] [raw]
Subject: Re: [PATCH v5 4/4] drm/i915: Get rid of intel_dp_dpcd_read_wake()

On Wed, Apr 13, 2016 at 10:58:33AM -0400, Lyude wrote:
> Since we've fixed up drm_dp_dpcd_read() to allow for retries when things
> timeout, there's no use for having this function anymore. Good riddens.
>
> Signed-off-by: Lyude <[email protected]>

All applied to drm-misc, thanks.
-Daniel

> ---
> drivers/gpu/drm/i915/intel_dp.c | 81 ++++++++++++-----------------------------
> 1 file changed, 23 insertions(+), 58 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> index 6c6f95a2..363629c 100644
> --- a/drivers/gpu/drm/i915/intel_dp.c
> +++ b/drivers/gpu/drm/i915/intel_dp.c
> @@ -3074,47 +3074,14 @@ static void chv_dp_post_pll_disable(struct intel_encoder *encoder)
> }
>
> /*
> - * Native read with retry for link status and receiver capability reads for
> - * cases where the sink may still be asleep.
> - *
> - * Sinks are *supposed* to come up within 1ms from an off state, but we're also
> - * supposed to retry 3 times per the spec.
> - */
> -static ssize_t
> -intel_dp_dpcd_read_wake(struct drm_dp_aux *aux, unsigned int offset,
> - void *buffer, size_t size)
> -{
> - ssize_t ret;
> - int i;
> -
> - /*
> - * Sometime we just get the same incorrect byte repeated
> - * over the entire buffer. Doing just one throw away read
> - * initially seems to "solve" it.
> - */
> - drm_dp_dpcd_read(aux, DP_DPCD_REV, buffer, 1);
> -
> - for (i = 0; i < 3; i++) {
> - ret = drm_dp_dpcd_read(aux, offset, buffer, size);
> - if (ret == size)
> - return ret;
> - msleep(1);
> - }
> -
> - return ret;
> -}
> -
> -/*
> * Fetch AUX CH registers 0x202 - 0x207 which contain
> * link status information
> */
> bool
> intel_dp_get_link_status(struct intel_dp *intel_dp, uint8_t link_status[DP_LINK_STATUS_SIZE])
> {
> - return intel_dp_dpcd_read_wake(&intel_dp->aux,
> - DP_LANE0_1_STATUS,
> - link_status,
> - DP_LINK_STATUS_SIZE) == DP_LINK_STATUS_SIZE;
> + return drm_dp_dpcd_read(&intel_dp->aux, DP_LANE0_1_STATUS, link_status,
> + DP_LINK_STATUS_SIZE) == DP_LINK_STATUS_SIZE;
> }
>
> /* These are source-specific values. */
> @@ -3749,8 +3716,8 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp)
> struct drm_i915_private *dev_priv = dev->dev_private;
> uint8_t rev;
>
> - if (intel_dp_dpcd_read_wake(&intel_dp->aux, 0x000, intel_dp->dpcd,
> - sizeof(intel_dp->dpcd)) < 0)
> + if (drm_dp_dpcd_read(&intel_dp->aux, 0x000, intel_dp->dpcd,
> + sizeof(intel_dp->dpcd)) < 0)
> return false; /* aux transfer failed */
>
> DRM_DEBUG_KMS("DPCD: %*ph\n", (int) sizeof(intel_dp->dpcd), intel_dp->dpcd);
> @@ -3758,8 +3725,8 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp)
> if (intel_dp->dpcd[DP_DPCD_REV] == 0)
> return false; /* DPCD not present */
>
> - if (intel_dp_dpcd_read_wake(&intel_dp->aux, DP_SINK_COUNT,
> - &intel_dp->sink_count, 1) < 0)
> + if (drm_dp_dpcd_read(&intel_dp->aux, DP_SINK_COUNT,
> + &intel_dp->sink_count, 1) < 0)
> return false;
>
> /*
> @@ -3782,9 +3749,9 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp)
> /* Check if the panel supports PSR */
> memset(intel_dp->psr_dpcd, 0, sizeof(intel_dp->psr_dpcd));
> if (is_edp(intel_dp)) {
> - intel_dp_dpcd_read_wake(&intel_dp->aux, DP_PSR_SUPPORT,
> - intel_dp->psr_dpcd,
> - sizeof(intel_dp->psr_dpcd));
> + drm_dp_dpcd_read(&intel_dp->aux, DP_PSR_SUPPORT,
> + intel_dp->psr_dpcd,
> + sizeof(intel_dp->psr_dpcd));
> if (intel_dp->psr_dpcd[0] & DP_PSR_IS_SUPPORTED) {
> dev_priv->psr.sink_support = true;
> DRM_DEBUG_KMS("Detected EDP PSR Panel.\n");
> @@ -3795,9 +3762,9 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp)
> uint8_t frame_sync_cap;
>
> dev_priv->psr.sink_support = true;
> - intel_dp_dpcd_read_wake(&intel_dp->aux,
> - DP_SINK_DEVICE_AUX_FRAME_SYNC_CAP,
> - &frame_sync_cap, 1);
> + drm_dp_dpcd_read(&intel_dp->aux,
> + DP_SINK_DEVICE_AUX_FRAME_SYNC_CAP,
> + &frame_sync_cap, 1);
> dev_priv->psr.aux_frame_sync = frame_sync_cap ? true : false;
> /* PSR2 needs frame sync as well */
> dev_priv->psr.psr2_support = dev_priv->psr.aux_frame_sync;
> @@ -3813,15 +3780,13 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp)
> /* Intermediate frequency support */
> if (is_edp(intel_dp) &&
> (intel_dp->dpcd[DP_EDP_CONFIGURATION_CAP] & DP_DPCD_DISPLAY_CONTROL_CAPABLE) &&
> - (intel_dp_dpcd_read_wake(&intel_dp->aux, DP_EDP_DPCD_REV, &rev, 1) == 1) &&
> + (drm_dp_dpcd_read(&intel_dp->aux, DP_EDP_DPCD_REV, &rev, 1) == 1) &&
> (rev >= 0x03)) { /* eDp v1.4 or higher */
> __le16 sink_rates[DP_MAX_SUPPORTED_RATES];
> int i;
>
> - intel_dp_dpcd_read_wake(&intel_dp->aux,
> - DP_SUPPORTED_LINK_RATES,
> - sink_rates,
> - sizeof(sink_rates));
> + drm_dp_dpcd_read(&intel_dp->aux, DP_SUPPORTED_LINK_RATES,
> + sink_rates, sizeof(sink_rates));
>
> for (i = 0; i < ARRAY_SIZE(sink_rates); i++) {
> int val = le16_to_cpu(sink_rates[i]);
> @@ -3844,9 +3809,9 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp)
> if (intel_dp->dpcd[DP_DPCD_REV] == 0x10)
> return true; /* no per-port downstream info */
>
> - if (intel_dp_dpcd_read_wake(&intel_dp->aux, DP_DOWNSTREAM_PORT_0,
> - intel_dp->downstream_ports,
> - DP_MAX_DOWNSTREAM_PORTS) < 0)
> + if (drm_dp_dpcd_read(&intel_dp->aux, DP_DOWNSTREAM_PORT_0,
> + intel_dp->downstream_ports,
> + DP_MAX_DOWNSTREAM_PORTS) < 0)
> return false; /* downstream port status fetch failed */
>
> return true;
> @@ -3860,11 +3825,11 @@ intel_dp_probe_oui(struct intel_dp *intel_dp)
> if (!(intel_dp->dpcd[DP_DOWN_STREAM_PORT_COUNT] & DP_OUI_SUPPORT))
> return;
>
> - if (intel_dp_dpcd_read_wake(&intel_dp->aux, DP_SINK_OUI, buf, 3) == 3)
> + if (drm_dp_dpcd_read(&intel_dp->aux, DP_SINK_OUI, buf, 3) == 3)
> DRM_DEBUG_KMS("Sink OUI: %02hx%02hx%02hx\n",
> buf[0], buf[1], buf[2]);
>
> - if (intel_dp_dpcd_read_wake(&intel_dp->aux, DP_BRANCH_OUI, buf, 3) == 3)
> + if (drm_dp_dpcd_read(&intel_dp->aux, DP_BRANCH_OUI, buf, 3) == 3)
> DRM_DEBUG_KMS("Branch OUI: %02hx%02hx%02hx\n",
> buf[0], buf[1], buf[2]);
> }
> @@ -3883,7 +3848,7 @@ intel_dp_probe_mst(struct intel_dp *intel_dp)
> if (intel_dp->dpcd[DP_DPCD_REV] < 0x12)
> return false;
>
> - if (intel_dp_dpcd_read_wake(&intel_dp->aux, DP_MSTM_CAP, buf, 1)) {
> + if (drm_dp_dpcd_read(&intel_dp->aux, DP_MSTM_CAP, buf, 1)) {
> if (buf[0] & DP_MST_CAP) {
> DRM_DEBUG_KMS("Sink is MST capable\n");
> intel_dp->is_mst = true;
> @@ -4020,7 +3985,7 @@ stop:
> static bool
> intel_dp_get_sink_irq(struct intel_dp *intel_dp, u8 *sink_irq_vector)
> {
> - return intel_dp_dpcd_read_wake(&intel_dp->aux,
> + return drm_dp_dpcd_read(&intel_dp->aux,
> DP_DEVICE_SERVICE_IRQ_VECTOR,
> sink_irq_vector, 1) == 1;
> }
> @@ -4030,7 +3995,7 @@ intel_dp_get_sink_irq_esi(struct intel_dp *intel_dp, u8 *sink_irq_vector)
> {
> int ret;
>
> - ret = intel_dp_dpcd_read_wake(&intel_dp->aux,
> + ret = drm_dp_dpcd_read(&intel_dp->aux,
> DP_SINK_COUNT_ESI,
> sink_irq_vector, 14);
> if (ret != 14)
> --
> 2.5.5
>
> _______________________________________________
> dri-devel mailing list
> [email protected]
> https://lists.freedesktop.org/mailman/listinfo/dri-devel

--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch