Re: [PATCH v4] backlight: pwm_bl: Fix uninitialized variable

From: Lee Jones
Date: Wed Jul 25 2018 - 04:04:02 EST


On Wed, 25 Jul 2018, Daniel Thompson wrote:

> Currently, if the DT does not define num-interpolated-steps then
> num_steps is undefined and the interpolation code will deploy randomly.
> Fix with a simple initialize to zero.
>
> Fixes: 573fe6d1c25c ("backlight: pwm_bl: Linear interpolation between brightness-levels")
> Reported-by: Marcel Ziswiler <marcel.ziswiler@xxxxxxxxxxx>
> Signed-off-by: Daniel Thompson <daniel.thompson@xxxxxxxxxx>
> Tested-by: Marcel Ziswiler <marcel.ziswiler@xxxxxxxxxxx>
> Reviewed-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
> Acked-by: Lee Jones <lee.jones@xxxxxxxxxx>
> ---
>
> Notes:
> v4:
> - Remove line break from Fixes: and update the *-by:s
>
> v3:
> - Switch to the simplest fix and zero the uninitialized variable. git
> grep indicates that ~25% of calls to of_property_read_u32() use this
> pattern (pre-initialize optional properties with sane values and
> ignore the return code).
>
> v2:
> - Simplify SoB chain (with Marcel's permission)
> - Separate complex if statement and make other similar calls use same
> return code checking approach
> - Tidy up comment formatting and fix pre-existing grammar error
>
> drivers/video/backlight/pwm_bl.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)

Applied, thanks.

--
Lee Jones [æçæ]
Linaro Services Technical Lead
Linaro.org â Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog