From: Gerd Hoffmann <kra...@redhat.com> 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: 1882...@bugs.launchpad.net Fixes: 3954ff10e06e ("drm/virtio: skip set_scanout if framebuffer didn't change") Signed-off-by: Gerd Hoffmann <kra...@redhat.com> Tested-by: Jiri Slaby <jirisl...@kernel.org> Tested-by: Diego Viola <diego.vi...@gmail.com> --- 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 af55b334be2f..35b5c80f5d85 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 + * independant 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 9ff9f4ac0522..4ab1b0ba2925 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 52d24179bcec..65757409d9ed 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, -- 2.28.0 -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1882851 Title: QEMU video freezes with "Guest disabled display" (virtio driver) Status in QEMU: New Bug description: I am using Arch Linux as my Guest and Host OS, after starting qemu with the following command: $ qemu-system-x86_64 -enable-kvm -hda arch-zoom.qcow2 -m 4G -vga virtio and waiting for a screen blank, I get this message: Guest disabled display And nothing happens after that, I can move the mouse or hit any key, and the message is still there. I can still reboot the VM but that's not optimal. I can reproduce this with the latest QEMU release (5.0.0) or git master, I also tried this with older releases (4.0.0, 3.0.0) and the issue is still there. I can't reproduce this with other video drivers (std, qxl). With std/qxl the screen will blank a bit and then continue as normal. To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1882851/+subscriptions