Re: [PATCH] Input: pmic8xxx-pwrkey - Set sane default for debounce time

From: Dmitry Torokhov
Date: Wed May 14 2014 - 15:03:03 EST


On Mon, Mar 31, 2014 at 11:29:27AM -0700, Stephen Boyd wrote:
> On 03/31/14 11:23, Dmitry Torokhov wrote:
> > On Mon, Mar 31, 2014 at 11:14:24AM -0700, Stephen Boyd wrote:
> >> If the debounce time is 0 our usage of ilog2() later on in this
> >> driver will cause undefined behavior. If CONFIG_OF=n this fact is
> >> evident to the compiler, and it emits a call to ____ilog2_NaN()
> >> which doesn't exist. Fix this by setting a sane default for
> >> debounce.
> >>
> >> Reported-by: Arnd Bergmann <arnd@xxxxxxxx>
> >> Signed-off-by: Stephen Boyd <sboyd@xxxxxxxxxxxxxx>
> >> ---
> >> drivers/input/misc/pmic8xxx-pwrkey.c | 2 +-
> >> 1 file changed, 1 insertion(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/input/misc/pmic8xxx-pwrkey.c b/drivers/input/misc/pmic8xxx-pwrkey.c
> >> index 1cb8fda7a166..27add04676e1 100644
> >> --- a/drivers/input/misc/pmic8xxx-pwrkey.c
> >> +++ b/drivers/input/misc/pmic8xxx-pwrkey.c
> >> @@ -92,7 +92,7 @@ static int pmic8xxx_pwrkey_probe(struct platform_device *pdev)
> >> bool pull_up;
> >>
> >> if (of_property_read_u32(pdev->dev.of_node, "debounce", &kpd_delay))
> >> - kpd_delay = 0;
> >> + kpd_delay = 15625;
> > What if somebody supplied 0 via DT? Can we check and return -EINVAL?
>
> Sure. Here's a v2.
>
> -----8<------
> From: Stephen Boyd <sboyd@xxxxxxxxxxxxxx>
> Subject: [PATCH v2] Input: pmic8xxx-pwrkey - Set sane default for debounce
> time
>
> If the debounce time is 0 our usage of ilog2() later on in this
> driver will cause undefined behavior. If CONFIG_OF=n this fact is
> evident to the compiler, and it emits a call to ____ilog2_NaN()
> which doesn't exist. Fix this by setting a sane default for
> debounce and failing to probe if debounce is 0 in the DT.
>
> Reported-by: Arnd Bergmann <arnd@xxxxxxxx>
> Signed-off-by: Stephen Boyd <sboyd@xxxxxxxxxxxxxx>

Applied, thank you. Sorry for the delay.

--
Dmitry
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