Re: [PATCH] pwm: samsung: Simplify using devm_pwmchip_add()

From: Krzysztof Kozlowski
Date: Wed Sep 01 2021 - 04:56:23 EST


On 01/09/2021 07:42, zhaoxiao wrote:
> With devm_pwmchip_add() we can drop pwmchip_remove() from the device
> remove callback. The latter can then go away, too and as this is the
> only user of platform_get_drvdata(), the respective call to
> platform_set_drvdata() can go, too.
>
> Signed-off-by: zhaoxiao <zhaoxiao@xxxxxxxxxxxxx>
> ---
> drivers/pwm/pwm-samsung.c | 18 +-----------------
> 1 file changed, 1 insertion(+), 17 deletions(-)
>
> diff --git a/drivers/pwm/pwm-samsung.c b/drivers/pwm/pwm-samsung.c
> index f6c528f02d43..b860a7b8bbdf 100644
> --- a/drivers/pwm/pwm-samsung.c
> +++ b/drivers/pwm/pwm-samsung.c
> @@ -560,9 +560,7 @@ static int pwm_samsung_probe(struct platform_device *pdev)
> chip->tclk0 = devm_clk_get(&pdev->dev, "pwm-tclk0");
> chip->tclk1 = devm_clk_get(&pdev->dev, "pwm-tclk1");
>
> - platform_set_drvdata(pdev, chip);

The test looks untested because this should cause bug during resume.
> -
> - ret = pwmchip_add(&chip->chip);
> + ret = devm_pwmchip_add(&pdev->dev, &chip->chip);
> if (ret < 0) {
> dev_err(dev, "failed to register PWM chip\n");
> clk_disable_unprepare(chip->base_clk);
> @@ -577,19 +575,6 @@ static int pwm_samsung_probe(struct platform_device *pdev)
> return 0;
> }
>
> -static int pwm_samsung_remove(struct platform_device *pdev)
> -{
> - struct samsung_pwm_chip *chip = platform_get_drvdata(pdev);
> - int ret;
> -
> - ret = pwmchip_remove(&chip->chip);
> - if (ret < 0)
> - return ret;
> -
> - clk_disable_unprepare(chip->base_clk);

NAK, the patch looks bad. You cannot remove some code from remove()
callback just "because".


Best regards,
Krzysztof