This is a note to let you know that I've just added the patch titled
drm/i915: Reserve enough fence slot for i915_vma_unbind_async
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drm-i915-reserve-enough-fence-slot-for-i915_vma_unbind_async.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 476fdcdaaae7b06c780cdfc234c704107f16c529 Mon Sep 17 00:00:00 2001
From: Nirmoy Das <nirmoy.das@xxxxxxxxx>
Date: Fri, 23 Dec 2022 10:20:11 +0100
Subject: drm/i915: Reserve enough fence slot for i915_vma_unbind_async
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From: Nirmoy Das <nirmoy.das@xxxxxxxxx>
commit 476fdcdaaae7b06c780cdfc234c704107f16c529 upstream.
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 <thomas.hellstrom@xxxxxxxxxxxxxxx>
Fixes: 2f6b90da9192 ("drm/i915: Use vma resources for async unbinding")
Cc: <stable@xxxxxxxxxxxxxxx> # v5.18+
Signed-off-by: Nirmoy Das <nirmoy.das@xxxxxxxxx>
Reviewed-by: Matthew Auld <matthew.auld@xxxxxxxxx>
Signed-off-by: Matthew Auld <matthew.auld@xxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20221223092011.11657-1-nirmoy.das@xxxxxxxxx
(cherry picked from commit 4f0755c2faf7388616109717facc5bbde6850e60)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/i915_vma.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/gpu/drm/i915/i915_vma.c
+++ b/drivers/gpu/drm/i915/i915_vma.c
@@ -2114,7 +2114,7 @@ int i915_vma_unbind_async(struct i915_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;
Patches currently in stable-queue which might be from nirmoy.das@xxxxxxxxx are
queue-6.1/drm-i915-reserve-enough-fence-slot-for-i915_vma_unbind_async.patch
