Patch "drm/vmwgfx: Make sure we unpin no longer needed buffers" has been added to the 5.11-stable tree

[gregkh at linuxfoundation.org]

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=summary

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 at vger.kernel.org> know about it.


>From ab4d9913632b1e5ffcf3365783e98718b3c83c7f Mon Sep 17 00:00:00 2001
From: Zack Rusin <zackr at 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 at 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 at vmware.com>
Reviewed-by: Martin Krastev <krastevm at vmware.com>
Reviewed-by: Roland Scheidegger <sroland at 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 at amd.com>
Cc: Christian König <christian.koenig at amd.com>
Cc: Daniel Vetter <daniel.vetter at intel.com>
Cc: Christian Koenig <christian.koenig at amd.com>
Cc: dri-devel at lists.freedesktop.org
Signed-off-by: Greg Kroah-Hartman <gregkh at 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 at vmware.com are

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