We get a lockdep splat when the reset mutex is held, because it can be taken from fence_wait. This conflicts with the mmu notifier we have, because we recurse between reset mutex and mmap lock -> mmu notifier.
Remove this recursion by calling revoke_mmaps before taking the lock.
The reset code still needs fixing, as taking mmap locks during reset is not allowed.
Signed-off-by: Maarten Lankhorst maarten.lankhorst@linux.intel.com Reviewed-by: Thomas Hellström thomas.hellstrom@linux.intel.com --- drivers/gpu/drm/i915/gt/intel_reset.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/i915/gt/intel_reset.c b/drivers/gpu/drm/i915/gt/intel_reset.c index 990cb4adbb9a..447f589750c2 100644 --- a/drivers/gpu/drm/i915/gt/intel_reset.c +++ b/drivers/gpu/drm/i915/gt/intel_reset.c @@ -970,8 +970,6 @@ static int do_reset(struct intel_gt *gt, intel_engine_mask_t stalled_mask) { int err, i;
- gt_revoke(gt); - err = __intel_gt_reset(gt, ALL_ENGINES); for (i = 0; err && i < RESET_MAX_RETRIES; i++) { msleep(10 * (i + 1)); @@ -1026,6 +1024,9 @@ void intel_gt_reset(struct intel_gt *gt,
might_sleep(); GEM_BUG_ON(!test_bit(I915_RESET_BACKOFF, >->reset.flags)); + + gt_revoke(gt); + mutex_lock(>->reset.mutex);
/* Clear any previous failed attempts at recovery. Time to try again. */