* [PATCH] pwm: spear: fix check on pwmchip_add() return value
@ 2014-05-05 21:29 Beniamino Galvani
2014-05-07 6:07 ` Viresh Kumar
0 siblings, 1 reply; 6+ messages in thread
From: Beniamino Galvani @ 2014-05-05 21:29 UTC (permalink / raw)
To: Thierry Reding; +Cc: linux-pwm, linux-kernel, Beniamino Galvani
pwmchip_add() returns zero on success and a negative value on error,
so the condition of the check must be inverted.
Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
---
drivers/pwm/pwm-spear.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/pwm/pwm-spear.c b/drivers/pwm/pwm-spear.c
index cb2d4f0..945556d 100644
--- a/drivers/pwm/pwm-spear.c
+++ b/drivers/pwm/pwm-spear.c
@@ -222,7 +222,7 @@ static int spear_pwm_probe(struct platform_device *pdev)
}
ret = pwmchip_add(&pc->chip);
- if (!ret) {
+ if (ret < 0) {
clk_unprepare(pc->clk);
dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
}
--
1.7.10.4
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH] pwm: spear: fix check on pwmchip_add() return value
2014-05-05 21:29 [PATCH] pwm: spear: fix check on pwmchip_add() return value Beniamino Galvani
@ 2014-05-07 6:07 ` Viresh Kumar
2014-05-07 8:24 ` Thierry Reding
0 siblings, 1 reply; 6+ messages in thread
From: Viresh Kumar @ 2014-05-07 6:07 UTC (permalink / raw)
To: Beniamino Galvani; +Cc: Thierry Reding, linux-pwm, linux-kernel@vger.kernel.org
On Tue, May 6, 2014 at 2:59 AM, Beniamino Galvani <b.galvani@gmail.com> wrote:
> pwmchip_add() returns zero on success and a negative value on error,
> so the condition of the check must be inverted.
>
> Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
> ---
> drivers/pwm/pwm-spear.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/pwm/pwm-spear.c b/drivers/pwm/pwm-spear.c
> index cb2d4f0..945556d 100644
> --- a/drivers/pwm/pwm-spear.c
> +++ b/drivers/pwm/pwm-spear.c
> @@ -222,7 +222,7 @@ static int spear_pwm_probe(struct platform_device *pdev)
> }
>
> ret = pwmchip_add(&pc->chip);
> - if (!ret) {
> + if (ret < 0) {
> clk_unprepare(pc->clk);
> dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
> }
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] pwm: spear: fix check on pwmchip_add() return value
2014-05-07 6:07 ` Viresh Kumar
@ 2014-05-07 8:24 ` Thierry Reding
2014-05-07 8:32 ` Viresh Kumar
0 siblings, 1 reply; 6+ messages in thread
From: Thierry Reding @ 2014-05-07 8:24 UTC (permalink / raw)
To: Viresh Kumar; +Cc: Beniamino Galvani, linux-pwm, linux-kernel@vger.kernel.org
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On Wed, May 07, 2014 at 11:37:25AM +0530, Viresh Kumar wrote:
> On Tue, May 6, 2014 at 2:59 AM, Beniamino Galvani <b.galvani@gmail.com> wrote:
> > pwmchip_add() returns zero on success and a negative value on error,
> > so the condition of the check must be inverted.
> >
> > Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
> > ---
> > drivers/pwm/pwm-spear.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/pwm/pwm-spear.c b/drivers/pwm/pwm-spear.c
> > index cb2d4f0..945556d 100644
> > --- a/drivers/pwm/pwm-spear.c
> > +++ b/drivers/pwm/pwm-spear.c
> > @@ -222,7 +222,7 @@ static int spear_pwm_probe(struct platform_device *pdev)
> > }
> >
> > ret = pwmchip_add(&pc->chip);
> > - if (!ret) {
> > + if (ret < 0) {
> > clk_unprepare(pc->clk);
> > dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
> > }
So the current code would run clk_unprepare() on success, but not on
failure. Does that cause any harm? Is the device still usable after
this? I'm asking because I'm not sure if this is linux-next material
or should be a fix for 3.15 (and possibly backported to stable).
Thierry
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^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] pwm: spear: fix check on pwmchip_add() return value
2014-05-07 8:24 ` Thierry Reding
@ 2014-05-07 8:32 ` Viresh Kumar
2014-05-07 8:49 ` Thierry Reding
0 siblings, 1 reply; 6+ messages in thread
From: Viresh Kumar @ 2014-05-07 8:32 UTC (permalink / raw)
To: Thierry Reding; +Cc: Beniamino Galvani, linux-pwm, linux-kernel@vger.kernel.org
On 7 May 2014 13:54, Thierry Reding <thierry.reding@gmail.com> wrote:
> So the current code would run clk_unprepare() on success, but not on
> failure. Does that cause any harm?
Yeah, that would make the device unusable as clk_enable will always fail.
> Is the device still usable after this?
Yes, this will fix the bug.
> I'm asking because I'm not sure if this is linux-next material
> or should be a fix for 3.15 (and possibly backported to stable).
IMO, it should be sent for stable: v3.8+
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] pwm: spear: fix check on pwmchip_add() return value
2014-05-07 8:32 ` Viresh Kumar
@ 2014-05-07 8:49 ` Thierry Reding
2014-05-07 8:53 ` Viresh Kumar
0 siblings, 1 reply; 6+ messages in thread
From: Thierry Reding @ 2014-05-07 8:49 UTC (permalink / raw)
To: Viresh Kumar; +Cc: Beniamino Galvani, linux-pwm, linux-kernel@vger.kernel.org
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On Wed, May 07, 2014 at 02:02:24PM +0530, Viresh Kumar wrote:
> On 7 May 2014 13:54, Thierry Reding <thierry.reding@gmail.com> wrote:
> > So the current code would run clk_unprepare() on success, but not on
> > failure. Does that cause any harm?
>
> Yeah, that would make the device unusable as clk_enable will always fail.
Hmm... so ever since this driver was merged in 3.8 it was completely
broken and nobody noticed? Interesting.
> > Is the device still usable after this?
>
> Yes, this will fix the bug.
>
> > I'm asking because I'm not sure if this is linux-next material
> > or should be a fix for 3.15 (and possibly backported to stable).
>
> IMO, it should be sent for stable: v3.8+
Since this was obviously broken since 3.8 and nobody noticed I wonder if
there's really an urgent need for this in stable.
Thierry
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^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2014-05-07 8:53 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
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2014-05-05 21:29 [PATCH] pwm: spear: fix check on pwmchip_add() return value Beniamino Galvani
2014-05-07 6:07 ` Viresh Kumar
2014-05-07 8:24 ` Thierry Reding
2014-05-07 8:32 ` Viresh Kumar
2014-05-07 8:49 ` Thierry Reding
2014-05-07 8:53 ` Viresh Kumar
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