Re: PWM regression causing failures with the pwm-atmel driver

From: Thorsten Leemhuis
Date: Tue Jun 20 2023 - 10:24:37 EST


On 22.05.23 17:19, Peter Rosin wrote:
>
> I have a device with a "sound card" that has an amplifier that needs
> an extra boost when high amplification is requested. This extra
> boost is controlled with a pwm-regulator.
>
> As of commit c73a3107624d ("pwm: Handle .get_state() failures") this
> device no longer works. I have tracked the problem to an unfortunate
> interaction between the underlying PWM driver and the PWM core.
> [...]>
> Approach 1. will maybe clobber the saved pwm->state such that
> it no longer works to get the period/duty_cycle if/when the
> PWM is disabled? Maybe only for some corner case? But that might
> be a significant corner case?
>
> Approach 2. will maybe mess up some unrelated functionality?
>
> Approach 3. is ugly, intrusive and is in all likelihood
> incomplete. It also needs a rebase from the culprit commit.
>
> #regzbot introduced c73a3107624d

What happened to this? There was quite a bit of discussion, but then
nothing happened anymore.

Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat)
--
Everything you wanna know about Linux kernel regression tracking:
https://linux-regtracking.leemhuis.info/about/#tldr
If I did something stupid, please tell me, as explained on that page.

#regzbot poke