From: Deepak Rawat drawat@vmware.com

SOU primary plane prepare_fb hook depends upon dmabuf_size to pin up BO (and not call a new vmw_dmabuf_init) when a new fb size is same as current fb. This was changed in a recent commit which is causing page_flip to fail on VM with low display memory and multi-mon failure when cycle monitors from secondary display.

Cc: stable@vger.kernel.org # 4.14, 4.16 Fixes: 20fb5a635a0c ("drm/vmwgfx: Unpin the screen object backup buffer when not used") Signed-off-by: Deepak Rawat drawat@vmware.com Reviewed-by: Sinclair Yeh syeh@vmware.com Signed-off-by: Thomas Hellstrom thellstrom@vmware.com --- drivers/gpu/drm/vmwgfx/vmwgfx_scrn.c | 2 ++ 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_scrn.c b/drivers/gpu/drm/vmwgfx/vmwgfx_scrn.c index 648f8127f65a..3d667e903beb 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_scrn.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_scrn.c @@ -482,6 +482,8 @@ vmw_sou_primary_plane_prepare_fb(struct drm_plane *plane, return ret; }

+ vps->dmabuf_size = size; + /* * TTM already thinks the buffer is pinned, but make sure the * pin_count is upped.