[PATCH v3] backlight: ktd253: Stabilize backlight

[Lee Jones]

On Tue, 13 Jul 2021, Linus Walleij wrote:

> On Fri, Jun 4, 2021 at 8:34 AM Linus Walleij <linus.walleij at linaro.org> wrote:
> 
> > Remove interrupt disablement during backlight setting. It is
> > way to dangerous and makes platforms instable by having it
> > miss vblank IRQs leading to the graphics derailing.
> >
> > The code is using ndelay() which is not available on
> > platforms such as ARM and will result in 32 * udelay(1)
> > which is substantial.
> >
> > Add some code to detect if an interrupt occurs during the
> > tight loop and in that case just redo it from the top.
> >
> > Fixes: 5317f37e48b9 ("backlight: Add Kinetic KTD253 backlight driver")
> > Cc: Stephan Gerhold <stephan at gerhold.net>
> > Reported-by: newbyte at disroot.org
> > Signed-off-by: Linus Walleij <linus.walleij at linaro.org>
> 
> Hm it seems this patch did not make it into v5.14-rc1, could it be applied
> as a fix for the -rc:s?

Ah, it was sent late in the cycle, so I postponed it.

> Shall I resend it with Daniel's ACK?

Yes please.

-- 
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
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