From a3c27df2ada92c0fb2758d03782871f5872f6b2c Mon Sep 17 00:00:00 2001 From: Thomas Zimmermann Date: Wed, 29 Jan 2020 13:05:31 +0100 Subject: [PATCH] drm/xen: Explicitly disable automatic sending of vblank event The atomic helpers automatically send out fake VBLANK events if no vblanking has been initialized. This would apply to xen, but xen has its own vblank logic. To avoid interfering with the atomic helpers, disable automatic vblank events explicitly. v5: * update comment v4: * separate commit from core vblank changes Signed-off-by: Thomas Zimmermann Acked-by: Gerd Hoffmann Reviewed-by: Daniel Vetter Reviewed-by: Oleksandr Andrushchenko Link: https://patchwork.freedesktop.org/patch/msgid/20200129120531.6891-16-tzimmermann@suse.de --- drivers/gpu/drm/xen/xen_drm_front_kms.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/drivers/gpu/drm/xen/xen_drm_front_kms.c b/drivers/gpu/drm/xen/xen_drm_front_kms.c index 4f34c5208180..78096bbcd226 100644 --- a/drivers/gpu/drm/xen/xen_drm_front_kms.c +++ b/drivers/gpu/drm/xen/xen_drm_front_kms.c @@ -220,6 +220,24 @@ static bool display_send_page_flip(struct drm_simple_display_pipe *pipe, return false; } +static int display_check(struct drm_simple_display_pipe *pipe, + struct drm_plane_state *plane_state, + struct drm_crtc_state *crtc_state) +{ + /* + * Xen doesn't initialize vblanking via drm_vblank_init(), so + * DRM helpers assume that it doesn't handle vblanking and start + * sending out fake VBLANK events automatically. + * + * As xen contains it's own logic for sending out VBLANK events + * in send_pending_event(), disable no_vblank (i.e., the xen + * driver has vblanking support). + */ + crtc_state->no_vblank = false; + + return 0; +} + static void display_update(struct drm_simple_display_pipe *pipe, struct drm_plane_state *old_plane_state) { @@ -284,6 +302,7 @@ static const struct drm_simple_display_pipe_funcs display_funcs = { .enable = display_enable, .disable = display_disable, .prepare_fb = drm_gem_fb_simple_display_pipe_prepare_fb, + .check = display_check, .update = display_update, };