[PATCH 0/1] drm/i915: Fix a deadlock that only affects 5.4

From: Sultan Alsawaf sultan@kerneltoast.com

Hi,

There's a mutex lock deadlock in i915 that only affects 5.4, but was fixed in 5.5. Normally, I would send a backport of the fix from 5.5, but the patch set that fixes the deadlock involves massive changes that are neither feasible nor desirable for backporting [1][2][3]. Therefore, I've made a small patch that only addresses the deadlock specifically for 5.4.

Thanks, Sultan

[1] 274cbf20fd10 ("drm/i915: Push the i915_active.retire into a worker") [2] 093b92287363 ("drm/i915: Split i915_active.mutex into an irq-safe spinlock for the rbtree") [3] 750bde2fd4ff ("drm/i915: Serialise with remote retirement")

Sultan Alsawaf (1): drm/i915: Fix ref->mutex deadlock in i915_active_wait()

drivers/gpu/drm/i915/i915_active.c | 27 +++++++++++++++++++++++---- drivers/gpu/drm/i915/i915_active.h | 4 ++-- 2 files changed, 25 insertions(+), 6 deletions(-)