On 06.03.24 09:18, Uwe Kleine-König wrote: > On Wed, Mar 06, 2024 at 08:05:15AM +0100, Linux regression tracking (Thorsten Leemhuis) wrote: >> >> Uwe, I noticed a report about a regression in bugzilla.kernel.org that >> apparently is caused by a change of yours. As many (most?) kernel >> developers don't keep an eye on it, I decided to forward it by mail. >> >> Note, you have to use bugzilla to reach the reporter, as I sadly[1] can >> not CCed them in mails like this. >> >> Quoting from https://bugzilla.kernel.org/show_bug.cgi?id=218559 : >> >>> Commit 76fe464c8e64e71b2e4af11edeef0e5d85eeb6aa ("leds: pwm: Don't >>> disable the PWM when the LED should be off") prevents stm32mp1xx based >>> targets from entering suspend if pwm-leds exist, as the stm32 PWM driver >>> refuses to enter suspend if any PWM channels are still active ("PWM 0 >>> still in use by consumer" see stm32_pwm_suspend in drivers/pwm/stm32-pwm.c). >>> >>> Reverting the mentioned commit fixes this behaviour but I'm not >>> certain if this is a problem with stm32-pwm or pwm-leds (what is the >>> usual behaviour for suspend with active PWM channels?). > > I'd assume the following patch fixes this report. I didn't test it > though. Jakob confirmed it helped in the bugzilla ticket. But the patch since then didn't make any progress afaics -- or did it and I just missed it in my search? 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 > ---->8---- > From: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx> > Subject: [PATCH] leds: pwm: Disable PWM when going to suspend > > On stm32mp1xx based machines (and others) a PWM consumer has to disable > the PWM because an enabled PWM refuses to suspend. So check the > LED_SUSPENDED flag and depending on that set the .enabled property. > > Link: https://bugzilla.kernel.org/show_bug.cgi?id=218559 > Fixes: 76fe464c8e64 ("leds: pwm: Don't disable the PWM when the LED should be off") > Signed-off-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx> > --- > drivers/leds/leds-pwm.c | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) > > diff --git a/drivers/leds/leds-pwm.c b/drivers/leds/leds-pwm.c > index 4e3936a39d0e..e1b414b40353 100644 > --- a/drivers/leds/leds-pwm.c > +++ b/drivers/leds/leds-pwm.c > @@ -53,7 +53,13 @@ static int led_pwm_set(struct led_classdev *led_cdev, > duty = led_dat->pwmstate.period - duty; > > led_dat->pwmstate.duty_cycle = duty; > - led_dat->pwmstate.enabled = true; > + /* > + * Disabling a PWM doesn't guarantee that it emits the inactive level. > + * So keep it on. Only for suspending the PWM should be disabled because > + * otherwise it refuses to suspend. The possible downside is that the > + * LED might stay (or even go) on. > + */ > + led_dat->pwmstate.enabled = !(led_cdev->flags & LED_SUSPENDED); > return pwm_apply_might_sleep(led_dat->pwm, &led_dat->pwmstate); > } > > base-commit: 15facbd7bd3dbfa04721cb71e69954eb4686cb9e > ---->8---- >
