From: Nirmoy Das Date: Fri, 23 Dec 2022 09:20:11 +0000 (+0100) Subject: drm/i915: Reserve enough fence slot for i915_vma_unbind_async X-Git-Tag: v6.6.7~1918^2~16^2~346 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=4f0755c2faf7388616109717facc5bbde6850e60;p=platform%2Fkernel%2Flinux-starfive.git drm/i915: Reserve enough fence slot for i915_vma_unbind_async A nested dma_resv_reserve_fences(1) will not reserve slot from the 2nd call onwards and folowing dma_resv_add_fence() might hit the "BUG_ON(fobj->num_fences >= fobj->max_fences)" check. I915 hit above nested dma_resv case in ttm_bo_handle_move_mem() with async unbind: dma_resv_reserve_fences() from --> ttm_bo_handle_move_mem() dma_resv_reserve_fences() from --> i915_vma_unbind_async() dma_resv_add_fence() from --> i915_vma_unbind_async() dma_resv_add_fence() from -->ttm_bo_move_accel_cleanup() Resolve this by adding an extra fence in i915_vma_unbind_async(). Suggested-by: Thomas Hellström Fixes: 2f6b90da9192 ("drm/i915: Use vma resources for async unbinding") Cc: # v5.18+ Signed-off-by: Nirmoy Das Reviewed-by: Matthew Auld Signed-off-by: Matthew Auld Link: https://patchwork.freedesktop.org/patch/msgid/20221223092011.11657-1-nirmoy.das@intel.com --- diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c index 8b16f6e..5272e2b 100644 --- a/drivers/gpu/drm/i915/i915_vma.c +++ b/drivers/gpu/drm/i915/i915_vma.c @@ -2149,7 +2149,7 @@ int i915_vma_unbind_async(struct i915_vma *vma, bool trylock_vm) if (!obj->mm.rsgt) return -EBUSY; - err = dma_resv_reserve_fences(obj->base.resv, 1); + err = dma_resv_reserve_fences(obj->base.resv, 2); if (err) return -EBUSY;