This is a note to let you know that I've just added the patch titled

drm/vmwgfx: Make sure we unpin no longer needed buffers

to the 5.11-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summ...

The filename of the patch is: drm-vmwgfx-make-sure-we-unpin-no-longer-needed-buffers.patch and it can be found in the queue-5.11 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From ab4d9913632b1e5ffcf3365783e98718b3c83c7f Mon Sep 17 00:00:00 2001

From: Zack Rusin zackr@vmware.com Date: Thu, 14 Jan 2021 18:38:16 -0500 Subject: drm/vmwgfx: Make sure we unpin no longer needed buffers MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit

From: Zack Rusin zackr@vmware.com

commit ab4d9913632b1e5ffcf3365783e98718b3c83c7f upstream.

We were not correctly unpinning no longer needed buffers. In particular vmw_buffer_object, which is internally often pinned on creation wasn't unpinned on destruction and none of the internal MOB buffers were unpinned before being put back. Technically this existed for a long time but commit 57fcd550eb15 ("drm/ttm: Warn on pinning without holding a reference") introduced a WARN_ON which was filling up the kernel logs rather quickly.

Quite frankly internal usage of vmw_buffer_object and in general pinning needs to be refactored in vmwgfx but for now this makes it work.

Signed-off-by: Zack Rusin zackr@vmware.com Reviewed-by: Martin Krastev krastevm@vmware.com Reviewed-by: Roland Scheidegger sroland@vmware.com Fixes: 57fcd550eb15 ("drm/ttm: Warn on pinning without holding a reference") Link: https://patchwork.freedesktop.org/patch/414984/?series=86052&rev=1 Cc: Huang Rui ray.huang@amd.com Cc: Christian König christian.koenig@amd.com Cc: Daniel Vetter daniel.vetter@intel.com Cc: Christian Koenig christian.koenig@amd.com Cc: dri-devel@lists.freedesktop.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/gpu/drm/vmwgfx/vmwgfx_drv.h | 2 ++ drivers/gpu/drm/vmwgfx/vmwgfx_mob.c | 4 ++++ 2 files changed, 6 insertions(+)

--- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h @@ -1554,6 +1554,8 @@ static inline void vmw_bo_unreference(st

*buf = NULL; if (tmp_buf != NULL) { + if (tmp_buf->base.pin_count > 0) + ttm_bo_unpin(&tmp_buf->base); ttm_bo_put(&tmp_buf->base); } } --- a/drivers/gpu/drm/vmwgfx/vmwgfx_mob.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_mob.c @@ -277,6 +277,7 @@ out_no_setup: &batch->otables[i]); }

+ ttm_bo_unpin(batch->otable_bo); ttm_bo_put(batch->otable_bo); batch->otable_bo = NULL; return ret; @@ -342,6 +343,7 @@ static void vmw_otable_batch_takedown(st vmw_bo_fence_single(bo, NULL); ttm_bo_unreserve(bo);

+ ttm_bo_unpin(batch->otable_bo); ttm_bo_put(batch->otable_bo); batch->otable_bo = NULL; } @@ -528,6 +530,7 @@ static void vmw_mob_pt_setup(struct vmw_ void vmw_mob_destroy(struct vmw_mob *mob) { if (mob->pt_bo) { + ttm_bo_unpin(mob->pt_bo); ttm_bo_put(mob->pt_bo); mob->pt_bo = NULL; } @@ -643,6 +646,7 @@ int vmw_mob_bind(struct vmw_private *dev out_no_cmd_space: vmw_fifo_resource_dec(dev_priv); if (pt_set_up) { + ttm_bo_unpin(mob->pt_bo); ttm_bo_put(mob->pt_bo); mob->pt_bo = NULL; }

Patches currently in stable-queue which might be from zackr@vmware.com are

queue-5.11/drm-vmwgfx-make-sure-we-unpin-no-longer-needed-buffers.patch