Re: [PATCH 0/4] Fix oops about sleeping in led_trigger_blink()

[Lee Jones <lee@kernel.org>]

On Tue, 25 Apr 2023, Hans de Goede wrote:

> Hi Lee,
> 
> On 4/20/23 15:56, Lee Jones wrote:
> > On Thu, 20 Apr 2023, Hans de Goede wrote:
> > 
> >> Hi Lee,
> >>
> >> On 4/20/23 13:36, Lee Jones wrote:
> >>> On Wed, 12 Apr 2023, Hans de Goede wrote:
> >>>
> >>>> Hi All,
> >>>>
> >>>> Here is a patch series to fix an oops about sleeping in led_trigger_blink()
> >>>> + one other small bugfix.
> >>>>
> >>>> Patches 1-3 should arguably have a:
> >>>>
> >>>> Fixes: 0b9536c95709 ("leds: Add ability to blink via simple trigger")
> >>>>
> >>>> tag, but Fixes tags tend to lead to patches getting automatically added
> >>>> to the stable series and I would prefer to see this series get some
> >>>> significant testing time in mainline first, so I have chosen to omit
> >>>> the tag.
> >>>
> >>> With subjects with the word "fix" in it, they will be hoovered up by the
> >>> Stable auto-picker anyway.
> >>
> >> Ok, in that case patch 3 should have:
> >>
> >> Fixes: 0b9536c95709 ("leds: Add ability to blink via simple trigger")
> >>
> >> Patches 1-2 are more preparation patches for this. Patch 2 does
> >> fix another race, but I'm not sure we ever hit that.
> >>
> >> Can you add the fixes tag while merging these, or do you
> >> want a v2 of this series ?
> > 
> > I'm holding out for either a Pavel review or some Tested-by's suggested
> > by Jacek.
> 
> Hmm, ok. I have asked Yauhen to give this a test since they have hit
> the oops/backtrace fixed by path 3/4 while testing the new leds-cht-wcove
> driver too.
> 
> But Yauhen has the same hw as me (I have already tested this on
> 3 different laptop models).
> 
> Note that Jacek did already give his Reviewed-by:
> 
> Reviewed-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
> 
> I think the bug this fixes was never an issue before because only
> very few triggers use regular blinking (rather then one-shot
> blinking which always uses the sw-blink implementation).
> 
> To hit this you need to use one of the few triggers which
> actually use regular-blinking in combination with a
> driver which supports hw-blinking and where its blink_set
> callbavck may sleep. It looks to me like no-one has hit
> this combination before. Which is why there are no bug reports
> for the issue and which also is why finding testers is going
> to be tricky.
> 
> I think that the best thing to do here is add this series to -next
> early in the upcoming cycle, so that it gets the maximum testing
> time possible in -next.

Agree.  Let's revisit this once the merge-window closes.

-- 
Lee Jones [李琼斯]