[PATCH 5.8 029/177] drm/virtio: fix unblank

Greg Kroah-Hartman
2020-09-15T23:35:25Z

From: Gerd Hoffmann <kraxel@redhat.com>

[ Upstream commit c6016c6e39c3ee8fd671532520be3cc13e439db2 ]

When going through a disable/enable cycle without changing the
framebuffer the optimization added by commit 3954ff10e06e ("drm/virtio:
skip set_scanout if framebuffer didn't change") causes the screen stay
blank. Add a bool to force an update to fix that.

v2: use drm_atomic_crtc_needs_modeset() (Daniel).

Cc: 1882851@bugs.launchpad.net
Fixes: 3954ff10e06e ("drm/virtio: skip set_scanout if framebuffer didn't change")
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Tested-by: Jiri Slaby <jirislaby@kernel.org>
Tested-by: Diego Viola <diego.viola@gmail.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20200818072511.6745-2-kraxel@redhat.com
(cherry picked from commit 1bc371cd0ec907bab870cacb6e898105f9c41dc8)
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpu/drm/virtio/virtgpu_display.c | 11 +++++++++++
drivers/gpu/drm/virtio/virtgpu_drv.h | 1 +
drivers/gpu/drm/virtio/virtgpu_plane.c | 4 +++-
3 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/virtio/virtgpu_display.c b/drivers/gpu/drm/virtio/virtgpu_display.c
index cc7fd957a3072..2b8421a35ab94 100644
--- a/drivers/gpu/drm/virtio/virtgpu_display.c
+++ b/drivers/gpu/drm/virtio/virtgpu_display.c
@@ -123,6 +123,17 @@ static int virtio_gpu_crtc_atomic_check(struct drm_crtc *crtc,
static void virtio_gpu_crtc_atomic_flush(struct drm_crtc *crtc,
struct drm_crtc_state *old_state)
{
+ struct virtio_gpu_output *output = drm_crtc_to_virtio_gpu_output(crtc);
+
+ /*
+ * virtio-gpu can't do modeset and plane update operations
+ * independent from each other. So the actual modeset happens
+ * in the plane update callback, and here we just check
+ * whenever we must force the modeset.
+ */
+ if (drm_atomic_crtc_needs_modeset(crtc->state)) {
+ output->needs_modeset = true;
+ }
}

static const struct drm_crtc_helper_funcs virtio_gpu_crtc_helper_funcs = {
diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.h b/drivers/gpu/drm/virtio/virtgpu_drv.h
index 9ff9f4ac0522a..4ab1b0ba29253 100644
--- a/drivers/gpu/drm/virtio/virtgpu_drv.h
+++ b/drivers/gpu/drm/virtio/virtgpu_drv.h
@@ -138,6 +138,7 @@ struct virtio_gpu_output {
int cur_x;
int cur_y;
bool enabled;
+ bool needs_modeset;
};
#define drm_crtc_to_virtio_gpu_output(x) \
container_of(x, struct virtio_gpu_output, crtc)
diff --git a/drivers/gpu/drm/virtio/virtgpu_plane.c b/drivers/gpu/drm/virtio/virtgpu_plane.c
index 52d24179bcecc..65757409d9ed1 100644
--- a/drivers/gpu/drm/virtio/virtgpu_plane.c
+++ b/drivers/gpu/drm/virtio/virtgpu_plane.c
@@ -163,7 +163,9 @@ static void virtio_gpu_primary_plane_update(struct drm_plane *plane,
plane->state->src_w != old_state->src_w ||
plane->state->src_h != old_state->src_h ||
plane->state->src_x != old_state->src_x ||
- plane->state->src_y != old_state->src_y) {
+ plane->state->src_y != old_state->src_y ||
+ output->needs_modeset) {
+ output->needs_modeset = false;
DRM_DEBUG("handle 0x%x, crtc %dx%d+%d+%d, src %dx%d+%d+%d\n",
bo->hw_res_handle,
plane->state->crtc_w, plane->state->crtc_h,
--
2.25.1