[PATCH] hwrng: mtk - Add remove function

[Guoqing Jiang]

On 8/26/24 13:17, Chen-Yu Tsai wrote:
> On Mon, Aug 26, 2024 at 9:45 AM Guoqing Jiang
> <guoqing.jiang at canonical.com> wrote:
>> Add mtk_rng_remove function which calles pm_runtime relevant funcs
>> and unregister hwrng to paired with mtk_rng_probe.
>>
>> And without remove function, pm_runtime complains below when reload
>> the driver.
>>
>> mtk_rng 1020f000.rng: Unbalanced pm_runtime_enable!
>>
>> Signed-off-by: Guoqing Jiang <guoqing.jiang at canonical.com>
>> ---
>>   drivers/char/hw_random/mtk-rng.c | 10 ++++++++++
>>   1 file changed, 10 insertions(+)
>>
>> diff --git a/drivers/char/hw_random/mtk-rng.c b/drivers/char/hw_random/mtk-rng.c
>> index 302e201b51c2..1b6aa9406b11 100644
>> --- a/drivers/char/hw_random/mtk-rng.c
>> +++ b/drivers/char/hw_random/mtk-rng.c
>> @@ -149,6 +149,15 @@ static int mtk_rng_probe(struct platform_device *pdev)
>>          return 0;
>>   }
>>
>> +static void mtk_rng_remove(struct platform_device *pdev)
>> +{
>> +        struct mtk_rng *priv = platform_get_drvdata(pdev);
>> +
>> +       pm_runtime_disable(&pdev->dev);
> Instead maybe just replace pm_runtime_enable() with devm_pm_runtime_enable()
> in the probe function?

Good point, will try it though it seems the function was not called by 
any hwrng driver so far.

>> +       pm_runtime_set_suspended(&pdev->dev);
> Not sure if this is needed? I'm not super familiar with runtime PM.
>
>> +       devm_hwrng_unregister(&pdev->dev, &priv->rng);
> The fact that it is already devm_* means that you shouldn't need to
> call it.

Okay, will remove the unnecessary calls.

Thanks,
Guoqing