Explain how to perform front-buffer rendering. v2: apply Pekka's rewrite
Signed-off-by: Simon Ser <cont...@emersion.fr> Cc: Pekka Paalanen <pekka.paala...@collabora.com> Cc: Simona Vetter <simona.vet...@ffwll.ch> --- drivers/gpu/drm/drm_blend.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/gpu/drm/drm_blend.c b/drivers/gpu/drm/drm_blend.c index 6e74de833466..4e83f372ea51 100644 --- a/drivers/gpu/drm/drm_blend.c +++ b/drivers/gpu/drm/drm_blend.c @@ -75,6 +75,12 @@ * the currently visible vertical area of the &drm_crtc. * FB_ID: * Mode object ID of the &drm_framebuffer this plane should scan out. + * + * When a KMS client is perfoming front-buffer rendering, it should set + * FB_ID to the same front-buffer FB on each atomic commit. This implies + * to the driver that it needs to re-read the same FB again. Otherwise + * drivers which do not employ continuously repeated scanout cycles might + * not update the screen. * CRTC_ID: * Mode object ID of the &drm_crtc this plane should be connected to. * -- 2.49.0
