[PATCH 63/64] drm/i915: Move gt_revoke() slightly

[Maarten Lankhorst]

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 at linux.intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom at 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 bf5b9f303a68..a281b7cd82d6 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, &gt->reset.flags));
+
+	gt_revoke(gt);
+
 	mutex_lock(&gt->reset.mutex);
 
 	/* Clear any previous failed attempts at recovery. Time to try again. */
-- 
2.30.0