drivers/i2c/busses/i2c-designware-common.c | 5 +++++ drivers/i2c/busses/i2c-designware-master.c | 21 ++++++++++++++++++++- 2 files changed, 25 insertions(+), 1 deletion(-)
From: "kimriver.liu" <kimriver.liu@siengine.com>
Failure in normal Stop operational path
This failure happens rarely and is hard to reproduce. Debug
trace showed that IC_STATUS had value of 0x23 when STOP_DET
occurred, immediately disable ENABLE bit that can result in
IC_RAW_INTR_STAT.MASTER_ON_HOLD holding SCL low.
Failure in ENABLE bit is disabled path
It was observed that master is holding SCL low and the
IC_ENABLE is already disabled, Enable ABORT bit and
ENABLE bit simultaneously cannot take effect.
Check if the master is holding SCL low after ENABLE bit is
already disabled. If SCL is held low, The software can set
this ABORT bit only when ENABLE is already set，otherwise,
the controller ignores any write to ABORT bit. When the
abort is done, then proceed with disabling the controller.
These kernel logs show up whenever an I2C transaction is
attempted after this failure.
i2c_designware e95e0000.i2c: timeout in disabling adapter
i2c_designware e95e0000.i2c: timeout waiting for bus ready
The patch can be fix the controller cannot be disabled while
SCL is held low in ENABLE bit is already disabled.
Signed-off-by: kimriver.liu <kimriver.liu@siengine.com>
---
drivers/i2c/busses/i2c-designware-common.c | 5 +++++
drivers/i2c/busses/i2c-designware-master.c | 21 ++++++++++++++++++++-
2 files changed, 25 insertions(+), 1 deletion(-)
diff --git a/drivers/i2c/busses/i2c-designware-common.c b/drivers/i2c/busses/i2c-designware-common.c
index e8a688d04aee..e1596b67e92f 100644
--- a/drivers/i2c/busses/i2c-designware-common.c
+++ b/drivers/i2c/busses/i2c-designware-common.c
@@ -453,6 +453,11 @@ void __i2c_dw_disable(struct dw_i2c_dev *dev)
abort_needed = raw_intr_stats & DW_IC_INTR_MST_ON_HOLD;
if (abort_needed) {
+ if (!enable) {
+ regmap_write(dev->map, DW_IC_ENABLE, DW_IC_ENABLE_ENABLE);
+ enable |= DW_IC_ENABLE_ENABLE;
+ usleep_range(25, 100);
+ }
regmap_write(dev->map, DW_IC_ENABLE, enable | DW_IC_ENABLE_ABORT);
ret = regmap_read_poll_timeout(dev->map, DW_IC_ENABLE, enable,
!(enable & DW_IC_ENABLE_ABORT), 10,
diff --git a/drivers/i2c/busses/i2c-designware-master.c b/drivers/i2c/busses/i2c-designware-master.c
index c7e56002809a..f86d03b0472a 100644
--- a/drivers/i2c/busses/i2c-designware-master.c
+++ b/drivers/i2c/busses/i2c-designware-master.c
@@ -253,6 +253,23 @@ static void i2c_dw_xfer_init(struct dw_i2c_dev *dev)
__i2c_dw_write_intr_mask(dev, DW_IC_INTR_MASTER_MASK);
}
+static int i2c_dw_check_mst_activity(struct dw_i2c_dev *dev)
+{
+ u32 status = 0;
+ int ret = 0;
+
+ regmap_read(dev->map, DW_IC_STATUS, &status);
+ if (status & DW_IC_STATUS_MASTER_ACTIVITY) {
+ ret = regmap_read_poll_timeout(dev->map, DW_IC_STATUS, status,
+ !(status & DW_IC_STATUS_MASTER_ACTIVITY),
+ 1100, 20000);
+ if (ret)
+ dev_err(dev->dev, "i2c mst activity not idle %d\n", ret);
+ }
+
+ return ret;
+}
+
static int i2c_dw_check_stopbit(struct dw_i2c_dev *dev)
{
u32 val;
@@ -796,7 +813,9 @@ i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
* additional interrupts are a hardware bug or this driver doesn't
* handle them correctly yet.
*/
- __i2c_dw_disable_nowait(dev);
+ ret = i2c_dw_check_mst_activity(dev);
+ if (!ret)
+ __i2c_dw_disable_nowait(dev);
if (dev->msg_err) {
ret = dev->msg_err;
--
2.17.1
On Wed, Sep 04, 2024 at 02:42:24PM +0800, kimriver liu wrote:
> From: "kimriver.liu" <kimriver.liu@siengine.com>
>
> Failure in normal Stop operational path
>
> This failure happens rarely and is hard to reproduce. Debug
> trace showed that IC_STATUS had value of 0x23 when STOP_DET
> occurred, immediately disable ENABLE bit that can result in
> IC_RAW_INTR_STAT.MASTER_ON_HOLD holding SCL low.
>
> Failure in ENABLE bit is disabled path
>
> It was observed that master is holding SCL low and the
> IC_ENABLE is already disabled, Enable ABORT bit and
> ENABLE bit simultaneously cannot take effect.
>
> Check if the master is holding SCL low after ENABLE bit is
> already disabled. If SCL is held low, The software can set
> this ABORT bit only when ENABLE is already set，otherwise,
> the controller ignores any write to ABORT bit. When the
> abort is done, then proceed with disabling the controller.
>
> These kernel logs show up whenever an I2C transaction is
> attempted after this failure.
> i2c_designware e95e0000.i2c: timeout in disabling adapter
> i2c_designware e95e0000.i2c: timeout waiting for bus ready
>
> The patch can be fix the controller cannot be disabled while
> SCL is held low in ENABLE bit is already disabled.
...
> abort_needed = raw_intr_stats & DW_IC_INTR_MST_ON_HOLD;
> if (abort_needed) {
> + if (!enable) {
> + regmap_write(dev->map, DW_IC_ENABLE, DW_IC_ENABLE_ENABLE);
> + enable |= DW_IC_ENABLE_ENABLE;
> + usleep_range(25, 100);
fsleep()
And add a short comment to explain the chosen value.
> + }
...
> +static int i2c_dw_check_mst_activity(struct dw_i2c_dev *dev)
> +{
> + u32 status = 0;
> + int ret = 0;
> +
> + regmap_read(dev->map, DW_IC_STATUS, &status);
> + if (status & DW_IC_STATUS_MASTER_ACTIVITY) {
> + ret = regmap_read_poll_timeout(dev->map, DW_IC_STATUS, status,
> + !(status & DW_IC_STATUS_MASTER_ACTIVITY),
> + 1100, 20000);
> + if (ret)
> + dev_err(dev->dev, "i2c mst activity not idle %d\n", ret);
> + }
> +
> + return ret;
This can be rewritten as
u32 status = 0;
int ret;
regmap_read(dev->map, DW_IC_STATUS, &status);
if (!status & DW_IC_STATUS_MASTER_ACTIVITY))
return 0;
ret = regmap_read_poll_timeout(dev->map, DW_IC_STATUS, status,
!(status & DW_IC_STATUS_MASTER_ACTIVITY),
1100, 20000);
if (ret)
dev_err(dev->dev, "i2c mst activity not idle %d\n", ret);
return ret;
> +}
...
> + ret = i2c_dw_check_mst_activity(dev);
> + if (!ret)
> + __i2c_dw_disable_nowait(dev);
...but looking at the usage, I think the proper is to have the above to return
boolean. And also update the name to follow the usual pattern for boolean helpers.
static bool i2c_dw_is_mst_idling(struct dw_i2c_dev *dev)
...
if (i2c_dw_is_mst_idling(dev))
__i2c_dw_disable_nowait(dev);
...
Also what does the heck "mst" stand for? Please, use decrypted words in
function names and error messages..
--
With Best Regards,
Andy Shevchenko
Andy Shevchenko:
Today, I followed your suggestion to resend the patch, but I found that
there is an inaccurate issue with determining whether i2c is enabled,
I will update the patch again this afternoon and send it to you. Thank you.
> abort_needed = raw_intr_stats & DW_IC_INTR_MST_ON_HOLD;
> if (abort_needed) {
- if (!enable) {
+ if (!(enable & DW_IC_ENABLE_ENABLE)) {
regmap_write(dev->map, DW_IC_ENABLE, DW_IC_ENABLE_ENABLE);
enable |= DW_IC_ENABLE_ENABLE;
Best Regards
Kimriver.liu
-----邮件原件-----
发件人: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
发送时间: 2024年9月4日 20:55
收件人: Liu Kimriver/刘金河 <kimriver.liu@siengine.com>
抄送: jarkko.nikula@linux.intel.com; mika.westerberg@linux.intel.com; jsd@semihalf.com; andi.shyti@kernel.org; linux-i2c@vger.kernel.org; linux-kernel@vger.kernel.org
主题: Re: [PATCH] i2c: designware: fix master is holding SCL low while ENABLE bit is disabled
On Wed, Sep 04, 2024 at 02:42:24PM +0800, kimriver liu wrote:
> From: "kimriver.liu" <kimriver.liu@siengine.com>
>
> Failure in normal Stop operational path
>
> This failure happens rarely and is hard to reproduce. Debug trace
> showed that IC_STATUS had value of 0x23 when STOP_DET occurred,
> immediately disable ENABLE bit that can result in
> IC_RAW_INTR_STAT.MASTER_ON_HOLD holding SCL low.
>
> Failure in ENABLE bit is disabled path
>
> It was observed that master is holding SCL low and the IC_ENABLE is
> already disabled, Enable ABORT bit and ENABLE bit simultaneously
> cannot take effect.
>
> Check if the master is holding SCL low after ENABLE bit is already
> disabled. If SCL is held low, The software can set this ABORT bit only
> when ENABLE is already set，otherwise,
> the controller ignores any write to ABORT bit. When the abort is done,
> then proceed with disabling the controller.
>
> These kernel logs show up whenever an I2C transaction is attempted
> after this failure.
> i2c_designware e95e0000.i2c: timeout in disabling adapter
> i2c_designware e95e0000.i2c: timeout waiting for bus ready
>
> The patch can be fix the controller cannot be disabled while SCL is
> held low in ENABLE bit is already disabled.
...
> abort_needed = raw_intr_stats & DW_IC_INTR_MST_ON_HOLD;
> if (abort_needed) {
> + if (!enable) {
> + regmap_write(dev->map, DW_IC_ENABLE, DW_IC_ENABLE_ENABLE);
> + enable |= DW_IC_ENABLE_ENABLE;
> + usleep_range(25, 100);
fsleep()
And add a short comment to explain the chosen value.
> + }
...
> +static int i2c_dw_check_mst_activity(struct dw_i2c_dev *dev) {
> + u32 status = 0;
> + int ret = 0;
> +
> + regmap_read(dev->map, DW_IC_STATUS, &status);
> + if (status & DW_IC_STATUS_MASTER_ACTIVITY) {
> + ret = regmap_read_poll_timeout(dev->map, DW_IC_STATUS, status,
> + !(status & DW_IC_STATUS_MASTER_ACTIVITY),
> + 1100, 20000);
> + if (ret)
> + dev_err(dev->dev, "i2c mst activity not idle %d\n", ret);
> + }
> +
> + return ret;
This can be rewritten as
u32 status = 0;
int ret;
regmap_read(dev->map, DW_IC_STATUS, &status);
if (!status & DW_IC_STATUS_MASTER_ACTIVITY))
return 0;
ret = regmap_read_poll_timeout(dev->map, DW_IC_STATUS, status,
!(status & DW_IC_STATUS_MASTER_ACTIVITY),
1100, 20000);
if (ret)
dev_err(dev->dev, "i2c mst activity not idle %d\n", ret);
return ret;
> +}
...
> + ret = i2c_dw_check_mst_activity(dev);
> + if (!ret)
> + __i2c_dw_disable_nowait(dev);
...but looking at the usage, I think the proper is to have the above to return boolean. And also update the name to follow the usual pattern for boolean helpers.
static bool i2c_dw_is_mst_idling(struct dw_i2c_dev *dev) ...
if (i2c_dw_is_mst_idling(dev))
__i2c_dw_disable_nowait(dev);
...
Also what does the heck "mst" stand for? Please, use decrypted words in function names and error messages..
--
With Best Regards,
Andy Shevchenko
Thanks for your suggestion. I will revise it according to your suggestions
and resend the patch.
Best Regards
-----邮件原件-----
发件人: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
发送时间: 2024年9月4日 20:55
收件人: Liu Kimriver/刘金河 <kimriver.liu@siengine.com>
抄送: jarkko.nikula@linux.intel.com; mika.westerberg@linux.intel.com; jsd@semihalf.com; andi.shyti@kernel.org; linux-i2c@vger.kernel.org; linux-kernel@vger.kernel.org
主题: Re: [PATCH] i2c: designware: fix master is holding SCL low while ENABLE bit is disabled
On Wed, Sep 04, 2024 at 02:42:24PM +0800, kimriver liu wrote:
> From: "kimriver.liu" <kimriver.liu@siengine.com>
>
> Failure in normal Stop operational path
>
> This failure happens rarely and is hard to reproduce. Debug trace
> showed that IC_STATUS had value of 0x23 when STOP_DET occurred,
> immediately disable ENABLE bit that can result in
> IC_RAW_INTR_STAT.MASTER_ON_HOLD holding SCL low.
>
> Failure in ENABLE bit is disabled path
>
> It was observed that master is holding SCL low and the IC_ENABLE is
> already disabled, Enable ABORT bit and ENABLE bit simultaneously
> cannot take effect.
>
> Check if the master is holding SCL low after ENABLE bit is already
> disabled. If SCL is held low, The software can set this ABORT bit only
> when ENABLE is already set，otherwise,
> the controller ignores any write to ABORT bit. When the abort is done,
> then proceed with disabling the controller.
>
> These kernel logs show up whenever an I2C transaction is attempted
> after this failure.
> i2c_designware e95e0000.i2c: timeout in disabling adapter
> i2c_designware e95e0000.i2c: timeout waiting for bus ready
>
> The patch can be fix the controller cannot be disabled while SCL is
> held low in ENABLE bit is already disabled.
...
> abort_needed = raw_intr_stats & DW_IC_INTR_MST_ON_HOLD;
> if (abort_needed) {
> + if (!enable) {
> + regmap_write(dev->map, DW_IC_ENABLE, DW_IC_ENABLE_ENABLE);
> + enable |= DW_IC_ENABLE_ENABLE;
> + usleep_range(25, 100);
fsleep()
And add a short comment to explain the chosen value.
> + }
...
> +static int i2c_dw_check_mst_activity(struct dw_i2c_dev *dev) {
> + u32 status = 0;
> + int ret = 0;
> +
> + regmap_read(dev->map, DW_IC_STATUS, &status);
> + if (status & DW_IC_STATUS_MASTER_ACTIVITY) {
> + ret = regmap_read_poll_timeout(dev->map, DW_IC_STATUS, status,
> + !(status & DW_IC_STATUS_MASTER_ACTIVITY),
> + 1100, 20000);
> + if (ret)
> + dev_err(dev->dev, "i2c mst activity not idle %d\n", ret);
> + }
> +
> + return ret;
This can be rewritten as
u32 status = 0;
int ret;
regmap_read(dev->map, DW_IC_STATUS, &status);
if (!status & DW_IC_STATUS_MASTER_ACTIVITY))
return 0;
ret = regmap_read_poll_timeout(dev->map, DW_IC_STATUS, status,
!(status & DW_IC_STATUS_MASTER_ACTIVITY),
1100, 20000);
if (ret)
dev_err(dev->dev, "i2c mst activity not idle %d\n", ret);
return ret;
> +}
...
> + ret = i2c_dw_check_mst_activity(dev);
> + if (!ret)
> + __i2c_dw_disable_nowait(dev);
...but looking at the usage, I think the proper is to have the above to return boolean. And also update the name to follow the usual pattern for boolean helpers.
static bool i2c_dw_is_mst_idling(struct dw_i2c_dev *dev) ...
if (i2c_dw_is_mst_idling(dev))
__i2c_dw_disable_nowait(dev);
...
Also what does the heck "mst" stand for? Please, use decrypted words in function names and error messages..
--
With Best Regards,
Andy Shevchenko
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