On Wed, Aug 23, 2017 at 9:34 PM, Pavel Machek <pavel@xxxxxx> wrote: >> On Tue, Jun 13, 2017 at 4:39 AM, Zhang Bo <bo.zhang@xxxxxxx> wrote: >> > This reverts commit 5ab92a7cb82c66bf30685583a38a18538e3807db. >> > >> > System cannot enter suspend mode because of heartbeat led trigger. >> > In autosleep_wq, try_to_suspend function will try to enter suspend >> > mode in specific period. it will get wakeup_count then call pm_notifier >> > chain callback function and freeze processes. >> > Heartbeat_pm_notifier is called and it call led_trigger_unregister to >> > change the trigger of led device to none. It will send uevent message >> > and the wakeup source count changed. As wakeup_count changed, suspend >> > will abort. >> > >> > Signed-off-by: Zhang Bo <bo.zhang@xxxxxxx> >> >> While investigating an heartbeat LED issue in v4.9.40-ltsi, I stumpled on this >> revert (commit 436c4c45b5b9562b ("Revert "leds: handle suspend/resume in >> heartbeat trigger"") in v4.12-rc6), which was not backported to v4.9 (yet). >> >> Interestingly, while running v4.9.x on r8a7791/koelsch with an LED configured >> for heartbeat, I can actually suspend the system using s2ram. >> However, after system resume the heartbeat LED no longer flashes. >> /sys/class/leds/LED6/trigger shows the trigger is still "none", and thus >> wasn't restored to "heartbeat" by the notifier. >> There's no "could not re-register heartbeat trigger" message printed. >> >> Backporting the revert fixes this. > > You have my Acked-by: if you want to submit this to some -stable > kernels... Thank you! Greg: Can you please queue 436c4c45b5b9562b ("Revert "leds: handle suspend/resume in heartbeat trigger"") for v4.9.x or v4.9-ltsi? Thanks! Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds