drm/virtio: send vblank event after crtc updates

virtio_gpu was failing to send vblank events when using the atomic IOCTL
with the DRM_MODE_PAGE_FLIP_EVENT flag set. This patch fixes each and
enables atomic pageflips updates.

Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Cc: stable@vger.kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/drivers/gpu/drm/virtio/virtgpu_display.c b/drivers/gpu/drm/virtio/virtgpu_display.c
index 4854dac87e24..5fd1fd06effc 100644
--- a/drivers/gpu/drm/virtio/virtgpu_display.c
+++ b/drivers/gpu/drm/virtio/virtgpu_display.c
@@ -267,11 +267,23 @@ static int virtio_gpu_crtc_atomic_check(struct drm_crtc *crtc,
         return 0;
 }
 
+static void virtio_gpu_crtc_atomic_flush(struct drm_crtc *crtc,
+                                         struct drm_crtc_state *old_state)
+{
+        unsigned long flags;
+
+        spin_lock_irqsave(&crtc->dev->event_lock, flags);
+        if (crtc->state->event)
+                drm_crtc_send_vblank_event(crtc, crtc->state->event);
+        spin_unlock_irqrestore(&crtc->dev->event_lock, flags);
+}
+
 static const struct drm_crtc_helper_funcs virtio_gpu_crtc_helper_funcs = {
         .enable        = virtio_gpu_crtc_enable,
         .disable       = virtio_gpu_crtc_disable,
         .mode_set_nofb = virtio_gpu_crtc_mode_set_nofb,
         .atomic_check  = virtio_gpu_crtc_atomic_check,
+        .atomic_flush  = virtio_gpu_crtc_atomic_flush,
 };
 
 static void virtio_gpu_enc_mode_set(struct drm_encoder *encoder,