Re: [ANNOUNCE] v5.4.17-rt9

From: Sebastian Andrzej Siewior
Date: Wed Feb 12 2020 - 05:20:13 EST


On 2020-02-07 07:11:06 [+0100], Mike Galbraith wrote:
> drm/i915/gt: use a LOCAL_IRQ_LOCK in __timeline_mark_lock()
>
> Quoting drm/i915/gt: Mark up the nested engine-pm timeline lock as irqsafe
>
> We use a fake timeline->mutex lock to reassure lockdep that the timeline
> is always locked when emitting requests. However, the use inside
> __engine_park() may be inside hardirq and so lockdep now complains about
> the mixed irq-state of the nested locked. Disable irqs around the
> lockdep tracking to keep it happy.
>
> This lockdep appeasement breaks RT because we take sleeping locks between
> __timeline_mark_lock()/unlock(). Use a LOCAL_IRQ_LOCK instead.
>
> Signed-off-by: Mike Galbraith <efaukt@xxxxxx>

Applied, thank you.

Sebastian