Re: [PATCH 5.10-rt+] drm/i915/gt: transform irq_disable into local_lock.

[Joe Korty <joe.korty@concurrent-rt.com>]

On Tue, Nov 16, 2021 at 04:39:24PM -0500, Steven Rostedt wrote:
> On Tue, 16 Nov 2021 22:02:49 +0100
> Sebastian Andrzej Siewior <bigeasy@linutronix.de> wrote:
> 
> > On 2021-11-16 15:25:34 [-0500], Steven Rostedt wrote:
> > > I'm looking to see what needs to be added to 5.10-rt. Is there a particular
> > > fix in one of the 5.x-rt trees (x > 10) that I can pull from? Or is this
> > > only an issue with 5.10 and below?  
> > 
> > I have this:
> >   https://lore.kernel.org/all/20211026114100.2593433-1-bigeasy@linutronix.de
> > 
> > pending vs upstream and I *think* more than just that one (2/9 from the
> > series) needs to be backported here. We do have 1/9 differently in 5.10,
> > not sure about 4/9.
> > I would love more feedback here from people and I tried to motivate Joe
> > to provide some. Clark was so nice to test these patches and provide
> > feedback. My i915 does not trigger all the code paths I'm touching
> > there.
> > 
> > If you think that 2/9 is obvious enough, please go ahead. If you start
> > touching that irq_work area then you might also want to pick
> >   810979682ccc9 ("irq_work: Allow irq_work_sync() to sleep if irq_work() no IRQ support.")
> >   b4c6f86ec2f64 ("irq_work: Handle some irq_work in a per-CPU thread on PREEMPT_RT")
> >   09089db79859c ("irq_work: Also rcuwait for !IRQ_WORK_HARD_IRQ on PREEMPT_RT")
> > 
> > which made their way into v5.16-rc1.
> >
> 
> I have a few boxes with i915, that maybe could help in testing.
> 
> I'll take a look.
> 
> -- Steve

Hi Steve, Sebastian,
I was on a no-Internet no-News vacation for the past week,
that is why I haven't responded.  Sorry.  In any case my
test stand suddenly started working, for no reason that I
can see, and so, for now, I have not been able to continue
my testing.

I will keep poking at it from time to time, see if I can
get the issue to come back.

Joe