Re: [PATCH v2 1/2] dt-bindings: pwm: dwc: add reset optional

Uwe Kleine-König
2026-03-17T09:42:41Z

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Hello,

On Mon, Mar 09, 2026 at 05:23:45PM +0800, Xuyang Dong wrote:
> The DesignWare PWM controller provides separate reset signals dedicated
> to each clock domain, as specified in the hardware documentation.
> Without asserting and deasserting these resets during probe, the PWM
> output may remain in an undefined state after system reboot.

Note there is an additional difficulty: A usual wish for machines with a
display is that the bootloader sets up a splash screen that is smoothly
taken over by Linux during boot. A reset of the PWM driving the
backlight then most probably results in a short dark display which
doesn't qualify for smooth.

So if you have a way to distinguish between "random state after
power-on" and "already programmed by the bootloader" this would be
great.

Best regards
Uwe

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