[PATCH v2 0/7] Rust Abstractions for PWM subsystem with TH1520 PWM driver

Drew Fustini drew at pdp7.com
Thu Jun 12 10:49:38 PDT 2025


On Thu, Jun 12, 2025 at 03:27:09PM +0200, Michal Wilczynski wrote:
> 
> 
> On 6/12/25 07:01, Uwe Kleine-König wrote:
> > Hello Drew,
> > 
> > On Wed, Jun 11, 2025 at 04:52:22PM -0700, Drew Fustini wrote:
> >> I also enabled the pwm fan driver. However, there is a probe failure:
> >>
> >> [    1.250921] pwm-fan pwm-fan: Failed to configure PWM: -524
> >> [    1.256546] pwm-fan pwm-fan: probe with driver pwm-fan failed with error -524
> > 
> > 524 = ENOTSUPP, so it seems the request had duty_offset > 0. Does your
> > fan use PWM_POLARITY_INVERTED? If so, try without that flag. If your fan
> > really needs an inverted PWM this of course makes fan control buggy.
> > With the next revision it should work fine (as a duty_offset > 0 should
> > get rounded down to 0).
> 
> Since we're running the same DT, the polarity shouldn't be inverted. I
> see you have CONFIG_PWM_DEBUG=y enabled, which is most likely the reason
> the probe fails.

Thanks, I've disabled that options and the probe completes okay. The fan
is now spinning :)

Drew



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