ui/gtk performs the following procedure to flush a scanout: 1) Queue a draw event. 2) The draw event gets triggered. 3) Blit the scanout to the framebuffer.
When flushing a DMA-BUF scanout, ui/gtk blocks the device before 2) if possible and unblocks it after 3). Blocking the device before 2) has two problems. First, it can leave the device blocked indefinitely because GTK sometimes decides to cancel 2) when the window is not visible for example. ui/gtk regularly repeats 1) as a workaround, but it is not applicable to GtkGLArea because it causes display corruption. Second, the behavior is inconsistent with the other types of scanout that leaves the device unblocked between 1) and 2). To fix these problems, let ui/gtk block the device after 2) instead. Note that the device is still blocked during 3) for DMA-BUF; this is because, unlike the other scanout types, 3) can happen asynchronously with the device for a DMA-BUF, and the device may simulatenously overwrite it, resulting in tearing, if it is left unblocked. With the problems fixed, the workaround to repeat 1) is no longer necessary and removed. Signed-off-by: Akihiko Odaki <[email protected]> --- ui/gtk-egl.c | 8 +------- ui/gtk-gl-area.c | 23 +---------------------- 2 files changed, 2 insertions(+), 29 deletions(-) diff --git a/ui/gtk-egl.c b/ui/gtk-egl.c index ae9239999cdb..61bb8d731ac5 100644 --- a/ui/gtk-egl.c +++ b/ui/gtk-egl.c @@ -91,6 +91,7 @@ void gd_egl_draw(VirtualConsole *vc) } else { qemu_dmabuf_set_draw_submitted(dmabuf, false); } + graphic_hw_gl_block(vc->gfx.dcl.con, true); } #endif gd_egl_scanout_flush(&vc->gfx.dcl, 0, 0, vc->gfx.w, vc->gfx.h); @@ -152,12 +153,6 @@ void gd_egl_refresh(DisplayChangeListener *dcl) gd_update_monitor_refresh_rate( vc, vc->window ? vc->window : vc->gfx.drawing_area); - if (vc->gfx.guest_fb.dmabuf && - qemu_dmabuf_get_draw_submitted(vc->gfx.guest_fb.dmabuf)) { - gd_egl_draw(vc); - return; - } - if (!vc->gfx.esurface) { gd_egl_init(vc); if (!vc->gfx.esurface) { @@ -408,7 +403,6 @@ void gd_egl_flush(DisplayChangeListener *dcl, if (vc->gfx.guest_fb.dmabuf && !qemu_dmabuf_get_draw_submitted(vc->gfx.guest_fb.dmabuf)) { - graphic_hw_gl_block(vc->gfx.dcl.con, true); qemu_dmabuf_set_draw_submitted(vc->gfx.guest_fb.dmabuf, true); gtk_egl_set_scanout_mode(vc, true); gtk_widget_queue_draw_area(area, x, y, w, h); diff --git a/ui/gtk-gl-area.c b/ui/gtk-gl-area.c index cd86022d264a..9e7ec7043037 100644 --- a/ui/gtk-gl-area.c +++ b/ui/gtk-gl-area.c @@ -86,6 +86,7 @@ void gd_gl_area_draw(VirtualConsole *vc) } else { qemu_dmabuf_set_draw_submitted(dmabuf, false); } + graphic_hw_gl_block(vc->gfx.dcl.con, true); } #endif @@ -163,27 +164,6 @@ void gd_gl_area_refresh(DisplayChangeListener *dcl) gd_update_monitor_refresh_rate(vc, vc->window ? vc->window : vc->gfx.drawing_area); - if (vc->gfx.guest_fb.dmabuf && - qemu_dmabuf_get_draw_submitted(vc->gfx.guest_fb.dmabuf)) { - /* - * gd_egl_refresh() calls gd_egl_draw() if a DMA-BUF draw has already - * been submitted, but this function does not call gd_gl_area_draw() in - * such a case due to display corruption. - * - * Calling gd_gl_area_draw() is necessary to prevent a situation where - * there is a scheduled draw event but it won't happen bacause the window - * is currently in inactive state (minimized or tabified). If draw is not - * done for a long time, gl_block timeout and/or fence timeout (on the - * guest) will happen eventually. - * - * However, it is found that calling gd_gl_area_draw() here causes guest - * display corruption on a Wayland Compositor. The display corruption is - * more serious than the possible fence timeout so gd_gl_area_draw() is - * omitted for now. - */ - return; - } - if (!vc->gfx.gls) { if (!gtk_widget_get_realized(vc->gfx.drawing_area)) { return; @@ -342,7 +322,6 @@ void gd_gl_area_scanout_flush(DisplayChangeListener *dcl, if (vc->gfx.guest_fb.dmabuf && !qemu_dmabuf_get_draw_submitted(vc->gfx.guest_fb.dmabuf)) { - graphic_hw_gl_block(vc->gfx.dcl.con, true); qemu_dmabuf_set_draw_submitted(vc->gfx.guest_fb.dmabuf, true); gtk_gl_area_set_scanout_mode(vc, true); } --- base-commit: 667e1fff878326c35c7f5146072e60a63a9a41c8 change-id: 20260115-gtk-424c2b910e65 Best regards, -- Akihiko Odaki <[email protected]>
