[0/8] drm/i915: PREEMPT_RT related fixups.

Message

Sebastian Andrzej Siewior Dec. 14, 2021, 2:02 p.m. UTC

Hi,

The following patches are from the PREEMPT_RT queue. One patch was
applied, one added so here are eight again. I can post them in smaller
batches if that is preferred.
It is mostly about disabling interrupts/preemption which leads to
problems.  Unfortunately DRM_I915_LOW_LEVEL_TRACEPOINTS had to be
disabled because it acquires locks from within trace points. Making the
lock a raw_spinlock_t led to higher latencies during video playback
  https://lore.kernel.org/all/[e-mail]/

and I'm not sure if I hit the worse case here.
I tested it on a SandyBridge with built-in i915 by using X, OpenGL and
playing videos without noticing any warnings. However, some code paths
were not entered.

Sebastian

Comments

Sebastian Andrzej Siewior Dec. 14, 2021, 4:12 p.m. UTC | #1

On 2021-12-14 15:58:45 [-0000], Patchwork wrote:
> == Series Details ==
> 
> Series: drm/i915: PREEMPT_RT related fixups. (rev4)
> URL   : https://patchwork.freedesktop.org/series/95463/
> State : failure
> 
> == Summary ==
> 
> Applying: drm/i915: Drop the irqs_disabled() check
> Applying: drm/i915/gt: Queue and wait for the irq_work item.
> Applying: drm/i915/gt: Use spin_lock_irq() instead of local_irq_disable() + spin_lock()
> Applying: drm/i915: Use preempt_disable/enable_rt() where recommended
> Applying: drm/i915: Don't disable interrupts on PREEMPT_RT during atomic updates
> Using index info to reconstruct a base tree...
> M	drivers/gpu/drm/i915/display/intel_crtc.c
> Falling back to patching base and 3-way merge...
> Auto-merging drivers/gpu/drm/i915/display/intel_crtc.c
> CONFLICT (content): Merge conflict in drivers/gpu/drm/i915/display/intel_crtc.c
> error: Failed to merge in the changes.
> hint: Use 'git am --show-current-patch=diff' to see the failed patch
> Patch failed at 0005 drm/i915: Don't disable interrupts on PREEMPT_RT during atomic updates
> When you have resolved this problem, run "git am --continue".
> If you prefer to skip this patch, run "git am --skip" instead.
> To restore the original branch and stop patching, run "git am --abort".

I used the drm-intel-gt-next branch. Which one would be preferred?

Sebastian