[PATCH v2] drm/vmwgfx: Don't memcmp equivalent pointers

[Ian Forbes]

These pointers are frequently the same and memcmp does not compare the
pointers before comparing their contents so this was wasting cycles
comparing 16 KiB of memory which will always be equal.

Fixes: bb6780aa5a1d ("drm/vmwgfx: Diff cursors when using cmds")
Signed-off-by: Ian Forbes <ian.forbes at broadcom.com>
Cc: <stable at vger.kernel.org> # v6.2+
---
v2: Fix code and commit message formatting.
--
 drivers/gpu/drm/vmwgfx/vmwgfx_kms.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
index cd4925346ed4..ef0af10c4968 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
@@ -216,7 +216,7 @@ static bool vmw_du_cursor_plane_has_changed(struct vmw_plane_state *old_vps,
 	new_image = vmw_du_cursor_plane_acquire_image(new_vps);
 
 	changed = false;
-	if (old_image && new_image)
+	if (old_image && new_image && old_image != new_image)
 		changed = memcmp(old_image, new_image, size) != 0;
 
 	return changed;
-- 
2.34.1