2018-09-07 13:20:05

by Anurag Kumar Vulisha

[permalink] [raw]
Subject: [PATCH v3 0/8] usb: dwc3: Fix broken BULK stream support to dwc3 gadget driver

These patch series fixes the broken BULK streaming support in
dwc3 gadget driver.

Changes in v3:
1. Added the changes suggested by "Thinh Nguyen"

Changes in v2:
1. Added "usb: dwc3:" in subject heading

Anurag Kumar Vulisha (8):
usb: dwc3: Correct the logic for checking TRB full in
__dwc3_prepare_one_trb()
usb: dwc3: update stream id in depcmd
usb: dwc3: make controller clear transfer resources after complete
usb: dwc3: implement stream transfer timeout
usb: dwc3: don't issue no-op trb for stream capable endpoints
usb: dwc3: check for requests in started list for stream capable
endpoints
usb: dwc3: Check for IOC/LST bit in both event->status and TRB->ctrl
fields
usb: dwc3: Check MISSED ISOC bit only for ISOC endpoints

drivers/usb/dwc3/core.h | 7 +++++
drivers/usb/dwc3/gadget.c | 78 ++++++++++++++++++++++++++++++++++++++++++-----
2 files changed, 77 insertions(+), 8 deletions(-)

--
2.1.1



2018-09-07 13:18:29

by Anurag Kumar Vulisha

[permalink] [raw]
Subject: [PATCH v3 6/8] usb: dwc3: check for requests in started list for stream capable endpoints

For stream capable endpoints, uas layer can queue mulpile requests on
single ep with different stream ids. So, there can be multiple pending
requests waiting to be transferred. This patch changes the code to check
for any pending requests waiting to be transferred on ep started_list and
calls __dwc3_gadget_kick_transfer() if any.

Signed-off-by: Anurag Kumar Vulisha <[email protected]>
Reviewed-by: Thinh Nguyen <[email protected]>
---
Changes in v3:
1. None

Changes in v2:
1. None
---
drivers/usb/dwc3/gadget.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 6936adf..e9901cc 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -2424,6 +2424,9 @@ static void dwc3_gadget_endpoint_transfer_in_progress(struct dwc3_ep *dep,

dwc3_gadget_ep_cleanup_completed_requests(dep, event, status);

+ if (dep->stream_capable && !list_empty(&dep->started_list))
+ __dwc3_gadget_kick_transfer(dep);
+
if (stop) {
dwc3_stop_active_transfer(dep, true);
dep->flags = DWC3_EP_ENABLED;
--
2.1.1


2018-09-07 13:18:38

by Anurag Kumar Vulisha

[permalink] [raw]
Subject: [PATCH v3 5/8] usb: dwc3: don't issue no-op trb for stream capable endpoints

The stream capable endpoints require stream id to be given
when issuing START TRANSFER. While issuing no-op trb the
stream id is not yet known, so don't issue no-op trb's on
stream capable endpoints.

Signed-off-by: Anurag Kumar Vulisha <[email protected]>
Reviewed-by: Thinh Nguyen <[email protected]>
---
Changes in v3:
1. None

Changes in v2:
1. None
---
drivers/usb/dwc3/gadget.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 98e5f39..6936adf 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -668,7 +668,7 @@ static int __dwc3_gadget_ep_enable(struct dwc3_ep *dep, unsigned int action)
* Issue StartTransfer here with no-op TRB so we can always rely on No
* Response Update Transfer command.
*/
- if (usb_endpoint_xfer_bulk(desc) ||
+ if ((usb_endpoint_xfer_bulk(desc) && !dep->stream_capable) ||
usb_endpoint_xfer_int(desc)) {
struct dwc3_gadget_ep_cmd_params params;
struct dwc3_trb *trb;
--
2.1.1


2018-09-07 13:18:40

by Anurag Kumar Vulisha

[permalink] [raw]
Subject: [PATCH v3 4/8] usb: dwc3: implement stream transfer timeout

According to dwc3 databook when streams are used, it may be possible
for the host and device become out of sync, where device may wait for
host to issue prime transcation and host may wait for device to issue
erdy. To avoid such deadlock, timeout needs to be implemented. After
timeout occurs, device will first stop transfer and restart the transfer
again. This patch does the same.

Signed-off-by: Anurag Kumar Vulisha <[email protected]>
Reviewed-by: Thinh Nguyen <[email protected]>
---
Changes in v3:
1. Added the changes suggested by "Thinh Nguyen"

Changes in v2:
1. Changed STREAM_TIMEOUT to STREAM_TIMEOUT_MS as suggested by
"Andy Shevchenko"
---
drivers/usb/dwc3/core.h | 7 +++++++
drivers/usb/dwc3/gadget.c | 36 ++++++++++++++++++++++++++++++++++++
2 files changed, 43 insertions(+)

diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index 5bfb625..0b255e97 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -633,6 +633,11 @@ struct dwc3_event_buffer {

#define DWC3_TRB_NUM 256

+/*
+ * Timeout value in msecs used by stream_timeout_timer when streams are enabled
+ */
+#define STREAM_TIMEOUT_MS 50
+
/**
* struct dwc3_ep - device side endpoint representation
* @endpoint: usb endpoint
@@ -656,6 +661,7 @@ struct dwc3_event_buffer {
* @name: a human readable name e.g. ep1out-bulk
* @direction: true for TX, false for RX
* @stream_capable: true when streams are enabled
+ * @stream_timeout_timer: timer used to aviod deadlock when streams are used
*/
struct dwc3_ep {
struct usb_ep endpoint;
@@ -705,6 +711,7 @@ struct dwc3_ep {

unsigned direction:1;
unsigned stream_capable:1;
+ struct timer_list stream_timeout_timer;
};

enum dwc3_phy {
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 13ea282..98e5f39 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -254,6 +254,7 @@ int dwc3_send_gadget_generic_command(struct dwc3 *dwc, unsigned cmd, u32 param)
}

static int __dwc3_gadget_wakeup(struct dwc3 *dwc);
+static void stream_timeout_function(struct timer_list *arg);

/**
* dwc3_send_gadget_ep_cmd - issue an endpoint command
@@ -574,6 +575,8 @@ static int dwc3_gadget_set_ep_config(struct dwc3_ep *dep, unsigned int action)
| DWC3_DEPCFG_STREAM_EVENT_EN
| DWC3_DEPCFG_XFER_COMPLETE_EN;
dep->stream_capable = true;
+ timer_setup(&dep->stream_timeout_timer,
+ stream_timeout_function, 0);
}

if (!usb_endpoint_xfer_control(desc))
@@ -730,6 +733,9 @@ static int __dwc3_gadget_ep_disable(struct dwc3_ep *dep)

trace_dwc3_gadget_ep_disable(dep);

+ if (dep->stream_capable)
+ del_timer(&dep->stream_timeout_timer);
+
dwc3_remove_requests(dwc, dep);

/* make sure HW endpoint isn't stalled */
@@ -1257,6 +1263,12 @@ static int __dwc3_gadget_kick_transfer(struct dwc3_ep *dep)
return ret;
}

+ if (starting && dep->stream_capable) {
+ dep->stream_timeout_timer.expires = jiffies +
+ msecs_to_jiffies(STREAM_TIMEOUT_MS);
+ add_timer(&dep->stream_timeout_timer);
+ }
+
return 0;
}

@@ -2403,6 +2415,13 @@ static void dwc3_gadget_endpoint_transfer_in_progress(struct dwc3_ep *dep,
stop = true;
}

+ /*
+ * Delete the timer that was started in __dwc3_gadget_kick_transfer()
+ * for stream capable endpoints.
+ */
+ if (dep->stream_capable)
+ del_timer(&dep->stream_timeout_timer);
+
dwc3_gadget_ep_cleanup_completed_requests(dep, event, status);

if (stop) {
@@ -2487,6 +2506,11 @@ static void dwc3_endpoint_interrupt(struct dwc3 *dwc,
}
break;
case DWC3_DEPEVT_STREAMEVT:
+ if (event->status == DEPEVT_STREAMEVT_FOUND)
+ del_timer(&dep->stream_timeout_timer);
+ else
+ dev_dbg(dwc->dev, "unable to find suitable stream");
+ break;
case DWC3_DEPEVT_RXTXFIFOEVT:
break;
}
@@ -2588,6 +2612,18 @@ static void dwc3_stop_active_transfer(struct dwc3_ep *dep, bool force)
}
}

+static void stream_timeout_function(struct timer_list *arg)
+{
+ struct dwc3_ep *dep = from_timer(dep, arg, stream_timeout_timer);
+ struct dwc3 *dwc = dep->dwc;
+ unsigned long flags;
+
+ spin_lock_irqsave(&dwc->lock, flags);
+ dwc3_stop_active_transfer(dep, true);
+ __dwc3_gadget_kick_transfer(dep);
+ spin_unlock_irqrestore(&dwc->lock, flags);
+}
+
static void dwc3_clear_stall_all_ep(struct dwc3 *dwc)
{
u32 epnum;
--
2.1.1


2018-09-07 13:20:16

by Anurag Kumar Vulisha

[permalink] [raw]
Subject: [PATCH v3 2/8] usb: dwc3: update stream id in depcmd

For stream capable endpoints, stream id related information
needs to be updated into DEPCMD while issuing START TRANSFER.
This patch does the same.

Signed-off-by: Anurag Kumar Vulisha <[email protected]>
Reviewed-by: Thinh Nguyen <[email protected]>
---
Changes in v3:
1. None

Changes in v2:
1. None
---
drivers/usb/dwc3/gadget.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 8a1622b..43d63a8 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -1224,6 +1224,9 @@ static int __dwc3_gadget_kick_transfer(struct dwc3_ep *dep)
params.param1 = lower_32_bits(req->trb_dma);
cmd = DWC3_DEPCMD_STARTTRANSFER;

+ if (dep->stream_capable)
+ cmd |= DWC3_DEPCMD_PARAM(req->request.stream_id);
+
if (usb_endpoint_xfer_isoc(dep->endpoint.desc))
cmd |= DWC3_DEPCMD_PARAM(dep->frame_number);
} else {
--
2.1.1


2018-09-07 13:20:32

by Anurag Kumar Vulisha

[permalink] [raw]
Subject: [PATCH v3 3/8] usb: dwc3: make controller clear transfer resources after complete

To start transfer with another stream id, controller needs to free
previously allocated transfer resource. This will be automatically
done by the controller at the time of XferComplete Event. This
patch updates the code to issue XferComplete event once all transfers
are done by setting LST bit in the ctrl field of the last TRB.

Signed-off-by: Anurag Kumar Vulisha <[email protected]>
Reviewed-by: Thinh Nguyen <[email protected]>
---
Changes in v3:
1. Added the changes suggested by "Thinh Nguyen"

Changes in v2:
1. None
---
drivers/usb/dwc3/gadget.c | 20 +++++++++++++++++---
1 file changed, 17 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 43d63a8..13ea282 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -571,7 +571,8 @@ static int dwc3_gadget_set_ep_config(struct dwc3_ep *dep, unsigned int action)

if (usb_ss_max_streams(comp_desc) && usb_endpoint_xfer_bulk(desc)) {
params.param1 |= DWC3_DEPCFG_STREAM_CAPABLE
- | DWC3_DEPCFG_STREAM_EVENT_EN;
+ | DWC3_DEPCFG_STREAM_EVENT_EN
+ | DWC3_DEPCFG_XFER_COMPLETE_EN;
dep->stream_capable = true;
}

@@ -995,6 +996,15 @@ static void __dwc3_prepare_one_trb(struct dwc3_ep *dep, struct dwc3_trb *trb,
if (chain)
trb->ctrl |= DWC3_TRB_CTRL_CHN;

+ /*
+ * To issue start transfer on another stream, controller need to free
+ * previously acquired transfer resource. Setting the LST bit in
+ * last TRB makes the controller clear transfer resource for that
+ * endpoint, allowing to start another stream on that endpoint.
+ */
+ else if (dep->stream_capable)
+ trb->ctrl |= DWC3_TRB_CTRL_LST;
+
if (usb_endpoint_xfer_bulk(dep->endpoint.desc) && dep->stream_capable)
trb->ctrl |= DWC3_TRB_CTRL_SID_SOFN(stream_id);

@@ -2268,7 +2278,7 @@ static int dwc3_gadget_ep_reclaim_completed_trb(struct dwc3_ep *dep,
if (event->status & DEPEVT_STATUS_SHORT && !chain)
return 1;

- if (event->status & DEPEVT_STATUS_IOC)
+ if (event->status & (DEPEVT_STATUS_IOC | DEPEVT_STATUS_LST))
return 1;

return 0;
@@ -2457,6 +2467,11 @@ static void dwc3_endpoint_interrupt(struct dwc3 *dwc,
}

switch (event->endpoint_event) {
+ case DWC3_DEPEVT_XFERCOMPLETE:
+ if (!dep->stream_capable)
+ break;
+ dep->flags &= ~DWC3_EP_TRANSFER_STARTED;
+ /* Fall Through */
case DWC3_DEPEVT_XFERINPROGRESS:
dwc3_gadget_endpoint_transfer_in_progress(dep, event);
break;
@@ -2472,7 +2487,6 @@ static void dwc3_endpoint_interrupt(struct dwc3 *dwc,
}
break;
case DWC3_DEPEVT_STREAMEVT:
- case DWC3_DEPEVT_XFERCOMPLETE:
case DWC3_DEPEVT_RXTXFIFOEVT:
break;
}
--
2.1.1


2018-09-07 13:20:37

by Anurag Kumar Vulisha

[permalink] [raw]
Subject: [PATCH v3 7/8] usb: dwc3: Check for IOC/LST bit in both event->status and TRB->ctrl fields

The present code in dwc3_gadget_ep_reclaim_completed_trb() will check
for IOC/LST bit in the event->status and returns if IOC/LST bit is
set. This logic doesn't work if multiple TRBs are queued per
request and the IOC/LST bit is set on the last TRB of that request.
Consider an example where a queued request has multiple queued TRBs
and IOC/LST bit is set only for the last TRB. In this case, the Core
generates XferComplete/XferInProgress events only for the last TRB
(since IOC/LST are set only for the last TRB). As per the logic in
dwc3_gadget_ep_reclaim_completed_trb() event->status is checked for
IOC/LST bit and returns on the first TRB. This makes the remaining
TRBs left unhandled.
To aviod this, changed the code to check for IOC/LST bits in both
event->status & TRB->ctrl. This patch does the same.

Signed-off-by: Anurag Kumar Vulisha <[email protected]>
Reviewed-by: Thinh Nguyen <[email protected]>
---
Changes in v3:
1. None

Changes in v2:
1. None
---
drivers/usb/dwc3/gadget.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index e9901cc..e1d4b73 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -2290,7 +2290,12 @@ static int dwc3_gadget_ep_reclaim_completed_trb(struct dwc3_ep *dep,
if (event->status & DEPEVT_STATUS_SHORT && !chain)
return 1;

- if (event->status & (DEPEVT_STATUS_IOC | DEPEVT_STATUS_LST))
+ if ((event->status & DEPEVT_STATUS_IOC) &&
+ (trb->ctrl & DWC3_TRB_CTRL_IOC))
+ return 1;
+
+ if ((event->status & DEPEVT_STATUS_LST) &&
+ (trb->ctrl & DWC3_TRB_CTRL_LST))
return 1;

return 0;
--
2.1.1


2018-09-07 13:21:22

by Anurag Kumar Vulisha

[permalink] [raw]
Subject: [PATCH v3 8/8] usb: dwc3: Check MISSED ISOC bit only for ISOC endpoints

When streaming is enabled on BULK endpoints and LST bit is set
observed MISSED ISOC bit set in event->status for BULK ep. Since
this bit is only valid for isocronous endpoints, changed the code
to check for isocrnous endpoints when MISSED ISOC bit is set.

Signed-off-by: Anurag Kumar Vulisha <[email protected]>
Reviewed-by: Thinh Nguyen <[email protected]>
---
Changes in v3:
1. None

Changes in v2:
1. None
---
drivers/usb/dwc3/gadget.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index e1d4b73..a4ead33 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -2413,7 +2413,8 @@ static void dwc3_gadget_endpoint_transfer_in_progress(struct dwc3_ep *dep,
if (event->status & DEPEVT_STATUS_BUSERR)
status = -ECONNRESET;

- if (event->status & DEPEVT_STATUS_MISSED_ISOC) {
+ if ((event->status & DEPEVT_STATUS_MISSED_ISOC) &&
+ usb_endpoint_xfer_isoc(dep->endpoint.desc)) {
status = -EXDEV;

if (list_empty(&dep->started_list))
--
2.1.1


2018-09-07 15:38:23

by Anurag Kumar Vulisha

[permalink] [raw]
Subject: [PATCH v3 1/8] usb: dwc3: Correct the logic for checking TRB full in __dwc3_prepare_one_trb()

Availability of TRB's are calculated using dwc3_calc_trbs_left(), which
determines available TRB's based on the HWO bit set in a TRB.

__dwc3_prepare_one_trb() is called with a TRB which needs to be prepared
for transfer. This __dwc3_prepare_one_trb() calls dwc3_calc_trbs_left()
to determine total available TRBs and set IOC bit if the total available
TRBs are zero. Since the present working TRB(which is passed as an
argument to __dwc3_prepare_one_trb() ) doesn't have HWO bit already set,
there are chances where dwc3_calc_trbs_left() wrongly calculates this
present working TRB as free(since the HWO bit is not yet set). This could
be a problem. This patch correct this issue by setting HWO bit before
calling dwc3_calc_trbs_left()

Signed-off-by: Anurag Kumar Vulisha <[email protected]>
Reviewed-by: Thinh Nguyen <[email protected]>
---
Changes in v3:
1. Corrected the logic for setting HWO bit as suggested by "Thinh Nguyen"

Changes in v2:
1. Changed the commit message
---
drivers/usb/dwc3/gadget.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 032ea7d..8a1622b 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -911,8 +911,6 @@ static void __dwc3_prepare_one_trb(struct dwc3_ep *dep, struct dwc3_trb *trb,
struct usb_gadget *gadget = &dwc->gadget;
enum usb_device_speed speed = gadget->speed;

- dwc3_ep_inc_enq(dep);
-
trb->size = DWC3_TRB_SIZE_LENGTH(length);
trb->bpl = lower_32_bits(dma);
trb->bph = upper_32_bits(dma);
@@ -991,7 +989,7 @@ static void __dwc3_prepare_one_trb(struct dwc3_ep *dep, struct dwc3_trb *trb,
}

if ((!no_interrupt && !chain) ||
- (dwc3_calc_trbs_left(dep) == 0))
+ (dwc3_calc_trbs_left(dep) == 1))
trb->ctrl |= DWC3_TRB_CTRL_IOC;

if (chain)
@@ -1002,6 +1000,8 @@ static void __dwc3_prepare_one_trb(struct dwc3_ep *dep, struct dwc3_trb *trb,

trb->ctrl |= DWC3_TRB_CTRL_HWO;

+ dwc3_ep_inc_enq(dep);
+
trace_dwc3_prepare_trb(dep, trb);
}

--
2.1.1


2018-09-07 23:29:43

by Thinh Nguyen

[permalink] [raw]
Subject: Re: [PATCH v3 4/8] usb: dwc3: implement stream transfer timeout

On 9/7/2018 6:14 AM, Anurag Kumar Vulisha wrote:
> According to dwc3 databook when streams are used, it may be possible
> for the host and device become out of sync, where device may wait for
> host to issue prime transcation and host may wait for device to issue
> erdy. To avoid such deadlock, timeout needs to be implemented. After
> timeout occurs, device will first stop transfer and restart the transfer
> again. This patch does the same.
>
> Signed-off-by: Anurag Kumar Vulisha <[email protected]>
> Reviewed-by: Thinh Nguyen <[email protected]>
> ---
> Changes in v3:
> 1. Added the changes suggested by "Thinh Nguyen"
>
> Changes in v2:
> 1. Changed STREAM_TIMEOUT to STREAM_TIMEOUT_MS as suggested by
> "Andy Shevchenko"
> ---
> drivers/usb/dwc3/core.h | 7 +++++++
> drivers/usb/dwc3/gadget.c | 36 ++++++++++++++++++++++++++++++++++++
> 2 files changed, 43 insertions(+)
>
> diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
> index 5bfb625..0b255e97 100644
> --- a/drivers/usb/dwc3/core.h
> +++ b/drivers/usb/dwc3/core.h
> @@ -633,6 +633,11 @@ struct dwc3_event_buffer {
>
> #define DWC3_TRB_NUM 256
>
> +/*
> + * Timeout value in msecs used by stream_timeout_timer when streams are enabled
> + */
> +#define STREAM_TIMEOUT_MS 50
> +
> /**
> * struct dwc3_ep - device side endpoint representation
> * @endpoint: usb endpoint
> @@ -656,6 +661,7 @@ struct dwc3_event_buffer {
> * @name: a human readable name e.g. ep1out-bulk
> * @direction: true for TX, false for RX
> * @stream_capable: true when streams are enabled
> + * @stream_timeout_timer: timer used to aviod deadlock when streams are used

Change aviod -> avoid. Also, the timer is being used when there's a
deadlock rather than to avoid it. You probably need to explain what
deadlock it is if you mentioned it here, but I think it's ok to simply
say timeout timer for streams (unless Felipe has any objection).

Thinh


2018-09-07 23:30:59

by Thinh Nguyen

[permalink] [raw]
Subject: Re: [PATCH v3 1/8] usb: dwc3: Correct the logic for checking TRB full in __dwc3_prepare_one_trb()

Hi Anurag,

On 9/7/2018 6:14 AM, Anurag Kumar Vulisha wrote:
> Availability of TRB's are calculated using dwc3_calc_trbs_left(), which
> determines available TRB's based on the HWO bit set in a TRB.
>
> __dwc3_prepare_one_trb() is called with a TRB which needs to be prepared
> for transfer. This __dwc3_prepare_one_trb() calls dwc3_calc_trbs_left()
> to determine total available TRBs and set IOC bit if the total available
> TRBs are zero. Since the present working TRB(which is passed as an
> argument to __dwc3_prepare_one_trb() ) doesn't have HWO bit already set,
> there are chances where dwc3_calc_trbs_left() wrongly calculates this
> present working TRB as free(since the HWO bit is not yet set). This could
> be a problem. This patch correct this issue by setting HWO bit before
> calling dwc3_calc_trbs_left()

Please revise your commit message to reflect your new change.

>
> Signed-off-by: Anurag Kumar Vulisha <[email protected]>
> Reviewed-by: Thinh Nguyen <[email protected]>
> ---
> Changes in v3:
> 1. Corrected the logic for setting HWO bit as suggested by "Thinh Nguyen"
>
> Changes in v2:
> 1. Changed the commit message
> ---
> drivers/usb/dwc3/gadget.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
> index 032ea7d..8a1622b 100644
> --- a/drivers/usb/dwc3/gadget.c
> +++ b/drivers/usb/dwc3/gadget.c
> @@ -911,8 +911,6 @@ static void __dwc3_prepare_one_trb(struct dwc3_ep *dep, struct dwc3_trb *trb,
> struct usb_gadget *gadget = &dwc->gadget;
> enum usb_device_speed speed = gadget->speed;
>
> - dwc3_ep_inc_enq(dep);
> -
> trb->size = DWC3_TRB_SIZE_LENGTH(length);
> trb->bpl = lower_32_bits(dma);
> trb->bph = upper_32_bits(dma);
> @@ -991,7 +989,7 @@ static void __dwc3_prepare_one_trb(struct dwc3_ep *dep, struct dwc3_trb *trb,
> }
>
> if ((!no_interrupt && !chain) ||
> - (dwc3_calc_trbs_left(dep) == 0))
> + (dwc3_calc_trbs_left(dep) == 1))
> trb->ctrl |= DWC3_TRB_CTRL_IOC;
>
> if (chain)
> @@ -1002,6 +1000,8 @@ static void __dwc3_prepare_one_trb(struct dwc3_ep *dep, struct dwc3_trb *trb,
>
> trb->ctrl |= DWC3_TRB_CTRL_HWO;
>
> + dwc3_ep_inc_enq(dep);
> +
> trace_dwc3_prepare_trb(dep, trb);
> }
>

BR,
Thinh

2018-09-08 03:52:05

by Anurag Kumar Vulisha

[permalink] [raw]
Subject: RE: [PATCH v3 1/8] usb: dwc3: Correct the logic for checking TRB full in __dwc3_prepare_one_trb()

Hi Thinh,

>On 9/7/2018 6:14 AM, Anurag Kumar Vulisha wrote:
>> Availability of TRB's are calculated using dwc3_calc_trbs_left(),
>> which determines available TRB's based on the HWO bit set in a TRB.
>>
>> __dwc3_prepare_one_trb() is called with a TRB which needs to be
>> prepared for transfer. This __dwc3_prepare_one_trb() calls
>> dwc3_calc_trbs_left() to determine total available TRBs and set IOC
>> bit if the total available TRBs are zero. Since the present working
>> TRB(which is passed as an argument to __dwc3_prepare_one_trb() )
>> doesn't have HWO bit already set, there are chances where
>> dwc3_calc_trbs_left() wrongly calculates this present working TRB as
>> free(since the HWO bit is not yet set). This could be a problem. This
>> patch correct this issue by setting HWO bit before calling
>> dwc3_calc_trbs_left()
>
>Please revise your commit message to reflect your new change.
>
Sorry , I missed updating the commit message. Thanks a lot for pointing, will fix it in next version

Thanks,
Anurag Kumar Vulisha
>>
>> Signed-off-by: Anurag Kumar Vulisha <[email protected]>
>> Reviewed-by: Thinh Nguyen <[email protected]>
>> ---
>> Changes in v3:
>> 1. Corrected the logic for setting HWO bit as suggested by "Thinh Nguyen"
>>
>> Changes in v2:
>> 1. Changed the commit message
>> ---
>> drivers/usb/dwc3/gadget.c | 6 +++---
>> 1 file changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
>> index 032ea7d..8a1622b 100644
>> --- a/drivers/usb/dwc3/gadget.c
>> +++ b/drivers/usb/dwc3/gadget.c
>> @@ -911,8 +911,6 @@ static void __dwc3_prepare_one_trb(struct dwc3_ep *dep,
>struct dwc3_trb *trb,
>> struct usb_gadget *gadget = &dwc->gadget;
>> enum usb_device_speed speed = gadget->speed;
>>
>> - dwc3_ep_inc_enq(dep);
>> -
>> trb->size = DWC3_TRB_SIZE_LENGTH(length);
>> trb->bpl = lower_32_bits(dma);
>> trb->bph = upper_32_bits(dma);
>> @@ -991,7 +989,7 @@ static void __dwc3_prepare_one_trb(struct dwc3_ep *dep,
>struct dwc3_trb *trb,
>> }
>>
>> if ((!no_interrupt && !chain) ||
>> - (dwc3_calc_trbs_left(dep) == 0))
>> + (dwc3_calc_trbs_left(dep) == 1))
>> trb->ctrl |= DWC3_TRB_CTRL_IOC;
>>
>> if (chain)
>> @@ -1002,6 +1000,8 @@ static void __dwc3_prepare_one_trb(struct
>> dwc3_ep *dep, struct dwc3_trb *trb,
>>
>> trb->ctrl |= DWC3_TRB_CTRL_HWO;
>>
>> + dwc3_ep_inc_enq(dep);
>> +
>> trace_dwc3_prepare_trb(dep, trb);
>> }
>>
>
>BR,
>Thinh

2018-09-08 03:52:05

by Anurag Kumar Vulisha

[permalink] [raw]
Subject: RE: [PATCH v3 4/8] usb: dwc3: implement stream transfer timeout


HI Thinh,

>> ---
>> drivers/usb/dwc3/core.h | 7 +++++++
>> drivers/usb/dwc3/gadget.c | 36 ++++++++++++++++++++++++++++++++++++
>> 2 files changed, 43 insertions(+)
>>
>> diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h index
>> 5bfb625..0b255e97 100644
>> --- a/drivers/usb/dwc3/core.h
>> +++ b/drivers/usb/dwc3/core.h
>> @@ -633,6 +633,11 @@ struct dwc3_event_buffer {
>>
>> #define DWC3_TRB_NUM 256
>>
>> +/*
>> + * Timeout value in msecs used by stream_timeout_timer when streams
>> +are enabled */
>> +#define STREAM_TIMEOUT_MS 50
>> +
>> /**
>> * struct dwc3_ep - device side endpoint representation
>> * @endpoint: usb endpoint
>> @@ -656,6 +661,7 @@ struct dwc3_event_buffer {
>> * @name: a human readable name e.g. ep1out-bulk
>> * @direction: true for TX, false for RX
>> * @stream_capable: true when streams are enabled
>> + * @stream_timeout_timer: timer used to aviod deadlock when streams
>> + are used
>
>Change aviod -> avoid. Also, the timer is being used when there's a deadlock rather
>than to avoid it. You probably need to explain what deadlock it is if you mentioned it
>here, but I think it's ok to simply say timeout timer for streams (unless Felipe has any
>objection).

Thanks for correcting again , will fix it in the next version of patch,

Thanks,
Anurag Kumar Vulisha