Commit 5b0a78ec authored by Maarten Lankhorst's avatar Maarten Lankhorst Committed by Daniel Vetter
Browse files

drm/i915: Move gt_revoke() slightly 



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: default avatarMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: default avatarThomas Hellström <thomas.hellstrom@linux.intel.com>
[danvet: Add FIXME.]
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210323155059.628690-64-maarten.lankhorst@linux.intel.com
parent fd995a3c

drivers/gpu/drm/i915/gt/intel_reset.c

+7 −2
Original line number Diff line number Diff line
@@ -974,8 +974,6 @@ 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));
@@ -1030,6 +1028,13 @@ void intel_gt_reset(struct intel_gt *gt, 


	might_sleep();

	GEM_BUG_ON(!test_bit(I915_RESET_BACKOFF, &gt->reset.flags));



	/*

	 * FIXME: Revoking cpu mmap ptes cannot be done from a dma_fence

	 * critical section like gpu reset.

	 */

	gt_revoke(gt);



	mutex_lock(&gt->reset.mutex);



	/* Clear any previous failed attempts at recovery. Time to try again. */