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

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@toradex.com Signed-off-by: Daniel Thompson daniel.thompson@linaro.org Tested-by: Marcel Ziswiler marcel.ziswiler@toradex.com Reviewed-by: Douglas Anderson dianders@chromium.org Acked-by: Lee Jones lee.jones@linaro.org

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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.