| Message ID | 20241215224752.220318-1-zmw12306@gmail.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | pwm: stm32: Add check for clk_enable() | expand |
Hello, On Sun, Dec 15, 2024 at 05:47:52PM -0500, Mingwei Zheng wrote: > Add check for the return value of clk_enable() to catch the potential > error. > > Fixes: 19f1016ea960 ("pwm: stm32: Fix enable count for clk in .probe()") > Signed-off-by: Mingwei Zheng <zmw12306@gmail.com> > Signed-off-by: Jiasheng Jiang <jiashengjiangcool@gmail.com> > --- > drivers/pwm/pwm-stm32.c | 7 +++++-- > 1 file changed, 5 insertions(+), 2 deletions(-) > > diff --git a/drivers/pwm/pwm-stm32.c b/drivers/pwm/pwm-stm32.c > index b889e64522c3..b94d186e3c0c 100644 > --- a/drivers/pwm/pwm-stm32.c > +++ b/drivers/pwm/pwm-stm32.c > @@ -858,8 +858,11 @@ static int stm32_pwm_probe(struct platform_device *pdev) > chip->ops = &stm32pwm_ops; > > /* Initialize clock refcount to number of enabled PWM channels. */ > - for (i = 0; i < num_enabled; i++) > - clk_enable(priv->clk); > + for (i = 0; i < num_enabled; i++) { > + ret = clk_enable(priv->clk); > + if (ret) > + return ret; > + } I wondered for some time if we could still improve more here. If the (say) second clk_enable() or devm_pwmchip_add() fails, the clk_enable() calls are leaked. However disabling the clk also might have downsides (as it might stop a running PWM). OTOH the only expected failure point is the first clk_enable() as the following are just software operations and devm_pwmchip_add() only fails on memory pressure. So proper cleanup doesn't really matter. So I think the patch is fine as is and I will apply it. Best regards Uwe
diff --git a/drivers/pwm/pwm-stm32.c b/drivers/pwm/pwm-stm32.c index b889e64522c3..b94d186e3c0c 100644 --- a/drivers/pwm/pwm-stm32.c +++ b/drivers/pwm/pwm-stm32.c @@ -858,8 +858,11 @@ static int stm32_pwm_probe(struct platform_device *pdev) chip->ops = &stm32pwm_ops; /* Initialize clock refcount to number of enabled PWM channels. */ - for (i = 0; i < num_enabled; i++) - clk_enable(priv->clk); + for (i = 0; i < num_enabled; i++) { + ret = clk_enable(priv->clk); + if (ret) + return ret; + } ret = devm_pwmchip_add(dev, chip); if (ret < 0)
Add check for the return value of clk_enable() to catch the potential error. Fixes: 19f1016ea960 ("pwm: stm32: Fix enable count for clk in .probe()") Signed-off-by: Mingwei Zheng <zmw12306@gmail.com> Signed-off-by: Jiasheng Jiang <jiashengjiangcool@gmail.com> --- drivers/pwm/pwm-stm32.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)