2023-10-19 22:28:00

by Frank Li

[permalink] [raw]
Subject: [PATCH v3 0/6] i3c: master: svc: collection of bugs fixes

Each patch is indepedents. See commit message for detail.

Change from v1 to v3.
See each patch notes

If there are notes between v2 to v3, that's means not change.

Frank Li (6):
i3c: master: svc: fix race condition in ibi work thread
i3c: master: svc: fix wrong data return when IBI happen during start
frame
i3c: master: svc: fix ibi may not return mandatory data byte
i3c: master: svc: fix check wrong status register in irq handler
i3c: master: svc: fix SDA keep low when polling IBIWON timeout happen
i3c: master: svc: fix random hot join failure since timeout error

drivers/i3c/master/svc-i3c-master.c | 51 ++++++++++++++++++++++++++++-
1 file changed, 50 insertions(+), 1 deletion(-)

--
2.34.1


2023-10-19 22:28:01

by Frank Li

[permalink] [raw]
Subject: [PATCH v3 1/6] i3c: master: svc: fix race condition in ibi work thread

The ibi work thread operates asynchronously with other transfers, such as
svc_i3c_master_priv_xfers(). Introduce mutex protection to ensure the
completion of the entire i3c/i2c transaction.

Fixes: dd3c52846d59 ("i3c: master: svc: Add Silvaco I3C master driver")
Cc: [email protected]
Reviewed-by: Miquel Raynal <[email protected]>
Signed-off-by: Frank Li <[email protected]>
---

Notes:
Change from v1 to v2
- update commit message
- Add Reviewed-by: Miquel Raynal <[email protected]>

drivers/i3c/master/svc-i3c-master.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)

diff --git a/drivers/i3c/master/svc-i3c-master.c b/drivers/i3c/master/svc-i3c-master.c
index d29de5fe533e6..8cd708c965085 100644
--- a/drivers/i3c/master/svc-i3c-master.c
+++ b/drivers/i3c/master/svc-i3c-master.c
@@ -174,6 +174,7 @@ struct svc_i3c_regs_save {
* @ibi.slots: Available IBI slots
* @ibi.tbq_slot: To be queued IBI slot
* @ibi.lock: IBI lock
+ * @lock: Transfer lock, protect between IBI work thread and callbacks from master
*/
struct svc_i3c_master {
struct i3c_master_controller base;
@@ -202,6 +203,7 @@ struct svc_i3c_master {
/* Prevent races within IBI handlers */
spinlock_t lock;
} ibi;
+ struct mutex lock;
};

/**
@@ -383,6 +385,7 @@ static void svc_i3c_master_ibi_work(struct work_struct *work)
u32 status, val;
int ret;

+ mutex_lock(&master->lock);
/* Acknowledge the incoming interrupt with the AUTOIBI mechanism */
writel(SVC_I3C_MCTRL_REQUEST_AUTO_IBI |
SVC_I3C_MCTRL_IBIRESP_AUTO,
@@ -459,6 +462,7 @@ static void svc_i3c_master_ibi_work(struct work_struct *work)

reenable_ibis:
svc_i3c_master_enable_interrupts(master, SVC_I3C_MINT_SLVSTART);
+ mutex_unlock(&master->lock);
}

static irqreturn_t svc_i3c_master_irq_handler(int irq, void *dev_id)
@@ -1203,9 +1207,11 @@ static int svc_i3c_master_send_bdcast_ccc_cmd(struct svc_i3c_master *master,
cmd->read_len = 0;
cmd->continued = false;

+ mutex_lock(&master->lock);
svc_i3c_master_enqueue_xfer(master, xfer);
if (!wait_for_completion_timeout(&xfer->comp, msecs_to_jiffies(1000)))
svc_i3c_master_dequeue_xfer(master, xfer);
+ mutex_unlock(&master->lock);

ret = xfer->ret;
kfree(buf);
@@ -1249,9 +1255,11 @@ static int svc_i3c_master_send_direct_ccc_cmd(struct svc_i3c_master *master,
cmd->read_len = read_len;
cmd->continued = false;

+ mutex_lock(&master->lock);
svc_i3c_master_enqueue_xfer(master, xfer);
if (!wait_for_completion_timeout(&xfer->comp, msecs_to_jiffies(1000)))
svc_i3c_master_dequeue_xfer(master, xfer);
+ mutex_unlock(&master->lock);

if (cmd->read_len != xfer_len)
ccc->dests[0].payload.len = cmd->read_len;
@@ -1308,9 +1316,11 @@ static int svc_i3c_master_priv_xfers(struct i3c_dev_desc *dev,
cmd->continued = (i + 1) < nxfers;
}

+ mutex_lock(&master->lock);
svc_i3c_master_enqueue_xfer(master, xfer);
if (!wait_for_completion_timeout(&xfer->comp, msecs_to_jiffies(1000)))
svc_i3c_master_dequeue_xfer(master, xfer);
+ mutex_unlock(&master->lock);

ret = xfer->ret;
svc_i3c_master_free_xfer(xfer);
@@ -1346,9 +1356,11 @@ static int svc_i3c_master_i2c_xfers(struct i2c_dev_desc *dev,
cmd->continued = (i + 1 < nxfers);
}

+ mutex_lock(&master->lock);
svc_i3c_master_enqueue_xfer(master, xfer);
if (!wait_for_completion_timeout(&xfer->comp, msecs_to_jiffies(1000)))
svc_i3c_master_dequeue_xfer(master, xfer);
+ mutex_unlock(&master->lock);

ret = xfer->ret;
svc_i3c_master_free_xfer(xfer);
@@ -1539,6 +1551,8 @@ static int svc_i3c_master_probe(struct platform_device *pdev)

INIT_WORK(&master->hj_work, svc_i3c_master_hj_work);
INIT_WORK(&master->ibi_work, svc_i3c_master_ibi_work);
+ mutex_init(&master->lock);
+
ret = devm_request_irq(dev, master->irq, svc_i3c_master_irq_handler,
IRQF_NO_SUSPEND, "svc-i3c-irq", master);
if (ret)
--
2.34.1

2023-10-19 22:28:07

by Frank Li

[permalink] [raw]
Subject: [PATCH v3 3/6] i3c: master: svc: fix ibi may not return mandatory data byte

MSTATUS[RXPEND] is only updated after the data transfer cycle started. This
creates an issue when the I3C clock is slow, and the CPU is running fast
enough that MSTATUS[RXPEND] may not be updated when the code reaches
checking point. As a result, mandatory data can be missed.

Add a wait for MSTATUS[COMPLETE] to ensure that all mandatory data is
already in FIFO. It also works without mandatory data.

Fixes: dd3c52846d59 ("i3c: master: svc: Add Silvaco I3C master driver")
Cc: [email protected]
Signed-off-by: Frank Li <[email protected]>
---

Notes:
Change from v2 to v3
- update commit message and add no mandatory data in commits message

Change from v1 to v2
- update commit message
it also works without mandatory bytes

Change from v1 to v2
- update commit message
it also works without mandatory bytes

drivers/i3c/master/svc-i3c-master.c | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/drivers/i3c/master/svc-i3c-master.c b/drivers/i3c/master/svc-i3c-master.c
index abebef666b2bb..dd06b7c9333f1 100644
--- a/drivers/i3c/master/svc-i3c-master.c
+++ b/drivers/i3c/master/svc-i3c-master.c
@@ -332,6 +332,7 @@ static int svc_i3c_master_handle_ibi(struct svc_i3c_master *master,
struct i3c_ibi_slot *slot;
unsigned int count;
u32 mdatactrl;
+ int ret, val;
u8 *buf;

slot = i3c_generic_ibi_get_free_slot(data->ibi_pool);
@@ -341,6 +342,13 @@ static int svc_i3c_master_handle_ibi(struct svc_i3c_master *master,
slot->len = 0;
buf = slot->data;

+ ret = readl_relaxed_poll_timeout(master->regs + SVC_I3C_MSTATUS, val,
+ SVC_I3C_MSTATUS_COMPLETE(val), 0, 1000);
+ if (ret) {
+ dev_err(master->dev, "Timeout when polling for COMPLETE\n");
+ return ret;
+ }
+
while (SVC_I3C_MSTATUS_RXPEND(readl(master->regs + SVC_I3C_MSTATUS)) &&
slot->len < SVC_I3C_FIFO_SIZE) {
mdatactrl = readl(master->regs + SVC_I3C_MDATACTRL);
--
2.34.1

2023-10-19 22:28:17

by Frank Li

[permalink] [raw]
Subject: [PATCH v3 5/6] i3c: master: svc: fix SDA keep low when polling IBIWON timeout happen

Upon IBIWON timeout, the SDA line will always be kept low if we don't emit
a stop. Calling svc_i3c_master_emit_stop() there will let the bus return to
idle state.

Call svc_i3c_master_emit_stop() to let i3c bus come back to idle statue
when IBIWON timeout happen.

Fixes: dd3c52846d59 ("i3c: master: svc: Add Silvaco I3C master driver")
Cc: [email protected]
Reviewed-by: Miquel Raynal <[email protected]>
Signed-off-by: Frank Li <[email protected]>
---

Notes:
Change from v2 to v3
- Update commit message and add review tag

Change from v1 to v2
- Update commite message

Change from v1 to v2
- Update commite message

drivers/i3c/master/svc-i3c-master.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/i3c/master/svc-i3c-master.c b/drivers/i3c/master/svc-i3c-master.c
index b113460f059c3..1a57fdebaa26d 100644
--- a/drivers/i3c/master/svc-i3c-master.c
+++ b/drivers/i3c/master/svc-i3c-master.c
@@ -404,6 +404,7 @@ static void svc_i3c_master_ibi_work(struct work_struct *work)
SVC_I3C_MSTATUS_IBIWON(val), 0, 1000);
if (ret) {
dev_err(master->dev, "Timeout when polling for IBIWON\n");
+ svc_i3c_master_emit_stop(master);
goto reenable_ibis;
}

--
2.34.1

2023-10-19 22:28:37

by Frank Li

[permalink] [raw]
Subject: [PATCH v3 4/6] i3c: master: svc: fix check wrong status register in irq handler

svc_i3c_master_irq_handler() wrong check register SVC_I3C_MINTMASKED. It
should be SVC_I3C_MSTATUS.

Fixes: dd3c52846d59 ("i3c: master: svc: Add Silvaco I3C master driver")
Cc: [email protected]
Reviewed-by: Miquel Raynal <[email protected]>
Signed-off-by: Frank Li <[email protected]>
---

Notes:
Change from v1 to v2
- Add Reviewed-by: Miquel Raynal <[email protected]>

drivers/i3c/master/svc-i3c-master.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/i3c/master/svc-i3c-master.c b/drivers/i3c/master/svc-i3c-master.c
index dd06b7c9333f1..b113460f059c3 100644
--- a/drivers/i3c/master/svc-i3c-master.c
+++ b/drivers/i3c/master/svc-i3c-master.c
@@ -476,7 +476,7 @@ static void svc_i3c_master_ibi_work(struct work_struct *work)
static irqreturn_t svc_i3c_master_irq_handler(int irq, void *dev_id)
{
struct svc_i3c_master *master = (struct svc_i3c_master *)dev_id;
- u32 active = readl(master->regs + SVC_I3C_MINTMASKED);
+ u32 active = readl(master->regs + SVC_I3C_MSTATUS);

if (!SVC_I3C_MSTATUS_SLVSTART(active))
return IRQ_NONE;
--
2.34.1

2023-10-19 22:28:37

by Frank Li

[permalink] [raw]
Subject: [PATCH v3 6/6] i3c: master: svc: fix random hot join failure since timeout error

master side report:
silvaco-i3c-master 44330000.i3c-master: Error condition: MSTATUS 0x020090c7, MERRWARN 0x00100000

BIT 20: TIMEOUT error
The module has stalled too long in a frame. This happens when:
- The TX FIFO or RX FIFO is not handled and the bus is stuck in the
middle of a message,
- No STOP was issued and between messages,
- IBI manual is used and no decision was made.
The maximum stall period is 100 μs.

This is a just warning. System irq thread schedule latency is possible
bigger than 100us. Just omit this waring.

Fixes: dd3c52846d59 ("i3c: master: svc: Add Silvaco I3C master driver")
Cc: [email protected]
Signed-off-by: Frank Li <[email protected]>
---

Notes:
Change from v2 to v3
- remove 10k at commit message

Change from v1 to v2
-none

Change from v1 to v2
-none

drivers/i3c/master/svc-i3c-master.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/drivers/i3c/master/svc-i3c-master.c b/drivers/i3c/master/svc-i3c-master.c
index 1a57fdebaa26d..fedb31e0076c4 100644
--- a/drivers/i3c/master/svc-i3c-master.c
+++ b/drivers/i3c/master/svc-i3c-master.c
@@ -93,6 +93,7 @@
#define SVC_I3C_MINTMASKED 0x098
#define SVC_I3C_MERRWARN 0x09C
#define SVC_I3C_MERRWARN_NACK BIT(2)
+#define SVC_I3C_MERRWARN_TIMEOUT BIT(20)
#define SVC_I3C_MDMACTRL 0x0A0
#define SVC_I3C_MDATACTRL 0x0AC
#define SVC_I3C_MDATACTRL_FLUSHTB BIT(0)
@@ -226,6 +227,11 @@ static bool svc_i3c_master_error(struct svc_i3c_master *master)
if (SVC_I3C_MSTATUS_ERRWARN(mstatus)) {
merrwarn = readl(master->regs + SVC_I3C_MERRWARN);
writel(merrwarn, master->regs + SVC_I3C_MERRWARN);
+
+ /* ignore timeout error */
+ if (merrwarn & SVC_I3C_MERRWARN_TIMEOUT)
+ return false;
+
dev_err(master->dev,
"Error condition: MSTATUS 0x%08x, MERRWARN 0x%08x\n",
mstatus, merrwarn);
--
2.34.1

2023-10-19 22:28:37

by Frank Li

[permalink] [raw]
Subject: [PATCH v3 2/6] i3c: master: svc: fix wrong data return when IBI happen during start frame

┌─────┐ ┏──┐ ┏──┐ ┏──┐ ┏──┐ ┏──┐ ┏──┐ ┏──┐ ┏──┐ ┌─────
SCL: ┘ └─────┛ └──┛ └──┛ └──┛ └──┛ └──┛ └──┛ └──┛ └──┘
───┐ ┌─────┐ ┌─────┐ ┌───────────┐
SDA: └───────────────────────┘ └─────┘ └─────┘ └─────
xxx╱ ╲╱ ╲╱ ╲╱ ╲╱ ╲
: xxx╲IBI ╱╲ Addr(0x0a) ╱╲ RW ╱╲NACK╱╲ S ╱

If an In-Band Interrupt (IBI) occurs and IBI work thread is not immediately
scheduled, When svc_i3c_master_priv_xfers() initiates the I3C transfer and
attempts to send address 0x7e, the target interprets it as an
IBI handler and returns the target address 0x0a.

However, svc_i3c_master_priv_xfers() does not handle this case and proceeds
with other transfers, resulting in incorrect data being returned.

Add IBIWON check in svc_i3c_master_xfer(). In case this situation occurs,
return a failure to the driver.

Fixes: dd3c52846d59 ("i3c: master: svc: Add Silvaco I3C master driver")
Cc: [email protected]
Reviewed-by: Miquel Raynal <[email protected]>
Signed-off-by: Frank Li <[email protected]>
---

Notes:
Change from v1 to v2
- update commit message
- fix typo yeild and falure

drivers/i3c/master/svc-i3c-master.c | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)

diff --git a/drivers/i3c/master/svc-i3c-master.c b/drivers/i3c/master/svc-i3c-master.c
index 8cd708c965085..abebef666b2bb 100644
--- a/drivers/i3c/master/svc-i3c-master.c
+++ b/drivers/i3c/master/svc-i3c-master.c
@@ -1010,6 +1010,9 @@ static int svc_i3c_master_xfer(struct svc_i3c_master *master,
u32 reg;
int ret;

+ /* clean SVC_I3C_MINT_IBIWON w1c bits */
+ writel(SVC_I3C_MINT_IBIWON, master->regs + SVC_I3C_MSTATUS);
+
writel(SVC_I3C_MCTRL_REQUEST_START_ADDR |
xfer_type |
SVC_I3C_MCTRL_IBIRESP_NACK |
@@ -1028,6 +1031,23 @@ static int svc_i3c_master_xfer(struct svc_i3c_master *master,
goto emit_stop;
}

+ /*
+ * According to I3C spec ver 1.1.1, 5.1.2.2.3 Consequence of Controller Starting a Frame
+ * with I3C Target Address.
+ *
+ * The I3C Controller normally should start a Frame, the Address may be arbitrated, and so
+ * the Controller shall monitor to see whether an In-Band Interrupt request, a Controller
+ * Role Request (i.e., Secondary Controller requests to become the Active Controller), or
+ * a Hot-Join Request has been made.
+ *
+ * If missed IBIWON check, the wrong data will be return. When IBIWON happen, return failure
+ * and yield the above events handler.
+ */
+ if (SVC_I3C_MSTATUS_IBIWON(reg)) {
+ ret = -ENXIO;
+ goto emit_stop;
+ }
+
if (rnw)
ret = svc_i3c_master_read(master, in, xfer_len);
else
--
2.34.1

2023-10-20 00:28:48

by Frank Li

[permalink] [raw]
Subject: Re: [PATCH v3 5/6] i3c: master: svc: fix SDA keep low when polling IBIWON timeout happen

On Thu, Oct 19, 2023 at 06:27:24PM -0400, Frank Li wrote:
> Upon IBIWON timeout, the SDA line will always be kept low if we don't emit
> a stop. Calling svc_i3c_master_emit_stop() there will let the bus return to
> idle state.
>
> Call svc_i3c_master_emit_stop() to let i3c bus come back to idle statue
> when IBIWON timeout happen.

I forget delete this line. will remove it at next version.

Frank.

>
> Fixes: dd3c52846d59 ("i3c: master: svc: Add Silvaco I3C master driver")
> Cc: [email protected]
> Reviewed-by: Miquel Raynal <[email protected]>
> Signed-off-by: Frank Li <[email protected]>
> ---
>
> Notes:
> Change from v2 to v3
> - Update commit message and add review tag
>
> Change from v1 to v2
> - Update commite message
>
> Change from v1 to v2
> - Update commite message
>
> drivers/i3c/master/svc-i3c-master.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/i3c/master/svc-i3c-master.c b/drivers/i3c/master/svc-i3c-master.c
> index b113460f059c3..1a57fdebaa26d 100644
> --- a/drivers/i3c/master/svc-i3c-master.c
> +++ b/drivers/i3c/master/svc-i3c-master.c
> @@ -404,6 +404,7 @@ static void svc_i3c_master_ibi_work(struct work_struct *work)
> SVC_I3C_MSTATUS_IBIWON(val), 0, 1000);
> if (ret) {
> dev_err(master->dev, "Timeout when polling for IBIWON\n");
> + svc_i3c_master_emit_stop(master);
> goto reenable_ibis;
> }
>
> --
> 2.34.1
>

2023-10-20 13:49:50

by Miquel Raynal

[permalink] [raw]
Subject: Re: [PATCH v3 3/6] i3c: master: svc: fix ibi may not return mandatory data byte

Hi Frank,

[email protected] wrote on Thu, 19 Oct 2023 18:27:22 -0400:

> MSTATUS[RXPEND] is only updated after the data transfer cycle started. This
> creates an issue when the I3C clock is slow, and the CPU is running fast
> enough that MSTATUS[RXPEND] may not be updated when the code reaches
> checking point. As a result, mandatory data can be missed.
>
> Add a wait for MSTATUS[COMPLETE] to ensure that all mandatory data is
> already in FIFO. It also works without mandatory data.
>
> Fixes: dd3c52846d59 ("i3c: master: svc: Add Silvaco I3C master driver")
> Cc: [email protected]
> Signed-off-by: Frank Li <[email protected]>

Reviewed-by: Miquel Raynal <[email protected]>

Thanks,
Miquèl

2023-10-20 13:51:41

by Miquel Raynal

[permalink] [raw]
Subject: Re: [PATCH v3 4/6] i3c: master: svc: fix check wrong status register in irq handler

Hi Frank,

[email protected] wrote on Thu, 19 Oct 2023 18:27:23 -0400:

> svc_i3c_master_irq_handler() wrong check register SVC_I3C_MINTMASKED. It

This sentence still needs to be corrected, please read carefully my
reviews.

> should be SVC_I3C_MSTATUS.
>
> Fixes: dd3c52846d59 ("i3c: master: svc: Add Silvaco I3C master driver")
> Cc: [email protected]
> Reviewed-by: Miquel Raynal <[email protected]>
> Signed-off-by: Frank Li <[email protected]>
> ---


Thanks,
Miquèl

2023-10-20 13:56:20

by Miquel Raynal

[permalink] [raw]
Subject: Re: [PATCH v3 2/6] i3c: master: svc: fix wrong data return when IBI happen during start frame

Hi Frank,

[email protected] wrote on Thu, 19 Oct 2023 18:27:21 -0400:

> ┌─────┐ ┏──┐ ┏──┐ ┏──┐ ┏──┐ ┏──┐ ┏──┐ ┏──┐ ┏──┐ ┌─────
> SCL: ┘ └─────┛ └──┛ └──┛ └──┛ └──┛ └──┛ └──┛ └──┛ └──┘
> ───┐ ┌─────┐ ┌─────┐ ┌───────────┐
> SDA: └───────────────────────┘ └─────┘ └─────┘ └─────
> xxx╱ ╲╱ ╲╱ ╲╱ ╲╱ ╲
> : xxx╲IBI ╱╲ Addr(0x0a) ╱╲ RW ╱╲NACK╱╲ S ╱
>
> If an In-Band Interrupt (IBI) occurs and IBI work thread is not immediately
> scheduled, When svc_i3c_master_priv_xfers() initiates the I3C transfer and

nit: when

> attempts to send address 0x7e, the target interprets it as an
> IBI handler and returns the target address 0x0a.
>
> However, svc_i3c_master_priv_xfers() does not handle this case and proceeds
> with other transfers, resulting in incorrect data being returned.
>
> Add IBIWON check in svc_i3c_master_xfer(). In case this situation occurs,
> return a failure to the driver.
>
> Fixes: dd3c52846d59 ("i3c: master: svc: Add Silvaco I3C master driver")
> Cc: [email protected]
> Reviewed-by: Miquel Raynal <[email protected]>
> Signed-off-by: Frank Li <[email protected]>
> ---


Thanks,
Miquèl