[v2,1/4] i2c: qcom-cci: Fix ordering of pm_runtime_xx and i2c_add_adapter
Commit Message
When we compile-in the CCI along with the imx412 driver and run on the RB5
we see that i2c_add_adapter() causes the probe of the imx412 driver to
happen.
This probe tries to perform an i2c xfer() and the xfer() in i2c-qcom-cci.c
fails on pm_runtime_get() because the i2c-qcom-cci.c::probe() function has
not completed to pm_runtime_enable(dev).
Fix this sequence by ensuring pm_runtime_xxx() calls happen prior to adding
the i2c adapter.
Fixes: e517526195de ("i2c: Add Qualcomm CCI I2C driver")
Reported-by: Vladimir Zapolskiy <vladimir.zapolskiy@linaro.org>
Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
---
drivers/i2c/busses/i2c-qcom-cci.c | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)
Comments
Hi Bryan,
On 5/24/22 17:02, Bryan O'Donoghue wrote:
> When we compile-in the CCI along with the imx412 driver and run on the RB5
> we see that i2c_add_adapter() causes the probe of the imx412 driver to
> happen.
>
> This probe tries to perform an i2c xfer() and the xfer() in i2c-qcom-cci.c
> fails on pm_runtime_get() because the i2c-qcom-cci.c::probe() function has
> not completed to pm_runtime_enable(dev).
>
> Fix this sequence by ensuring pm_runtime_xxx() calls happen prior to adding
> the i2c adapter.
>
it's a proper root cause disclosure and the fix, thank you.
> Fixes: e517526195de ("i2c: Add Qualcomm CCI I2C driver")
> Reported-by: Vladimir Zapolskiy <vladimir.zapolskiy@linaro.org>
> Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
> ---
> drivers/i2c/busses/i2c-qcom-cci.c | 14 +++++++++-----
> 1 file changed, 9 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-qcom-cci.c b/drivers/i2c/busses/i2c-qcom-cci.c
> index 5c7cc862f08f..90d02effeae9 100644
> --- a/drivers/i2c/busses/i2c-qcom-cci.c
> +++ b/drivers/i2c/busses/i2c-qcom-cci.c
> @@ -638,6 +638,11 @@ static int cci_probe(struct platform_device *pdev)
> if (ret < 0)
> goto error;
>
> + pm_runtime_set_autosuspend_delay(dev, MSEC_PER_SEC);
> + pm_runtime_use_autosuspend(dev);
> + pm_runtime_set_active(dev);
> + pm_runtime_enable(dev);
> +
> for (i = 0; i < cci->data->num_masters; i++) {
> if (!cci->master[i].cci)
> continue;
> @@ -649,14 +654,13 @@ static int cci_probe(struct platform_device *pdev)
> }
> }
>
> - pm_runtime_set_autosuspend_delay(dev, MSEC_PER_SEC);
> - pm_runtime_use_autosuspend(dev);
> - pm_runtime_set_active(dev);
> - pm_runtime_enable(dev);
> -
> return 0;
>
> error_i2c:
> + pm_runtime_put(dev);
Here pm_runtime_put(dev) should be removed, there is no pm_runtime_get*(dev) above,
otherwise PM usage counter underflow issues are expected.
> + pm_runtime_disable(dev);
> + pm_runtime_dont_use_autosuspend(dev);
> +
> for (--i ; i >= 0; i--) {
> if (cci->master[i].cci) {
> i2c_del_adapter(&cci->master[i].adap);
With the correction stated above please feel free to add my tags:
Reviewed-by: Vladimir Zapolskiy <vladimir.zapolskiy@linaro.org>
Tested-by: Vladimir Zapolskiy <vladimir.zapolskiy@linaro.org>
--
Best wishes,
Vladimir
@@ -638,6 +638,11 @@ static int cci_probe(struct platform_device *pdev)
if (ret < 0)
goto error;
+ pm_runtime_set_autosuspend_delay(dev, MSEC_PER_SEC);
+ pm_runtime_use_autosuspend(dev);
+ pm_runtime_set_active(dev);
+ pm_runtime_enable(dev);
+
for (i = 0; i < cci->data->num_masters; i++) {
if (!cci->master[i].cci)
continue;
@@ -649,14 +654,13 @@ static int cci_probe(struct platform_device *pdev)
}
}
- pm_runtime_set_autosuspend_delay(dev, MSEC_PER_SEC);
- pm_runtime_use_autosuspend(dev);
- pm_runtime_set_active(dev);
- pm_runtime_enable(dev);
-
return 0;
error_i2c:
+ pm_runtime_put(dev);
+ pm_runtime_disable(dev);
+ pm_runtime_dont_use_autosuspend(dev);
+
for (--i ; i >= 0; i--) {
if (cci->master[i].cci) {
i2c_del_adapter(&cci->master[i].adap);