On Thu, 29 Jul 2021 16:01:35 +0800
Hui Liu <hui.liu@xxxxxxxxxxxx> wrote:
> Add mutex_destroy when probe fail and remove device.
>
> Signed-off-by: Hui Liu <hui.liu@xxxxxxxxxxxx>
Hi Hui Liu,
Two things here.
1) You need to explain with a clear example flow when this would serve a
useful purpose. As I explained before, we do no in general put mutex_destroy()
in remove paths as it is usually just noise.
2) It's in the wrong order logically. mutex init is between the clk_prepare_enable
and iio_device_register, hence if we are going to have mutex destroy it must also
be in that that location (remove should be reverse of probe or there should be
a clear comment explaining why we need to do things in a different order.
3) If touching this code at all, please move all of the probe / remove to devm_
managed code so that we don't need to get this ordering right at all because
it will be done automatically.
So I won't apply this without 1 and even if I accepted the principle, it's
still in the wrong place in remove.
Jonathan
> ---
> drivers/iio/adc/mt6577_auxadc.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/iio/adc/mt6577_auxadc.c b/drivers/iio/adc/mt6577_auxadc.c
> index 79c1dd68b909..d57243037ad6 100644
> --- a/drivers/iio/adc/mt6577_auxadc.c
> +++ b/drivers/iio/adc/mt6577_auxadc.c
> @@ -289,6 +289,7 @@ static int mt6577_auxadc_probe(struct platform_device *pdev)
> ret = iio_device_register(indio_dev);
> if (ret < 0) {
> dev_err(&pdev->dev, "failed to register iio device\n");
> + mutex_destroy(&adc_dev->lock);
> goto err_power_off;
> }
>
> @@ -313,6 +314,7 @@ static int mt6577_auxadc_remove(struct platform_device *pdev)
> 0, MT6577_AUXADC_PDN_EN);
>
> clk_disable_unprepare(adc_dev->adc_clk);
> + mutex_destroy(&adc_dev->lock);
>
> return 0;
> }
