On Thu, 16 Jan 2025 16:25:35 +0000 Simon Ser <cont...@emersion.fr> wrote:
> It's not obvious off-hand which CRTCs will get a page-flip event
> when using this flag in an atomic commit, because it's all
> implicitly implied based on the contents of the atomic commit.
> Document requirements for using this flag and
>
and?
> Note, because prepare_signaling() runs right after
> drm_atomic_set_property() calls, page-flip events are not delivered
> for CRTCs pulled in later by DRM core (e.g. on modeset by
> drm_atomic_helper_check_modeset()) or the driver (e.g. other CRTCs
> sharing a DP-MST connector).
>
> Signed-off-by: Simon Ser <cont...@emersion.fr>
> Cc: Simona Vetter <simona.vet...@ffwll.ch>
> Cc: Ville Syrjälä <ville.syrj...@linux.intel.com>
> Cc: Pekka Paalanen <pekka.paala...@collabora.com>
> Cc: David Turner <david.tur...@raspberrypi.com>
> ---
> include/uapi/drm/drm_mode.h | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/include/uapi/drm/drm_mode.h b/include/uapi/drm/drm_mode.h
> index c082810c08a8..a122bea25593 100644
> --- a/include/uapi/drm/drm_mode.h
> +++ b/include/uapi/drm/drm_mode.h
> @@ -962,6 +962,14 @@ struct hdr_output_metadata {
> * Request that the kernel sends back a vblank event (see
> * struct drm_event_vblank) with the &DRM_EVENT_FLIP_COMPLETE type when the
> * page-flip is done.
> + *
> + * When used with atomic uAPI, one event will be delivered per CRTC included
> in
> + * the atomic commit. A CRTC is included in an atomic commit if one of its
> + * properties is set, or if a property is set on a connector or plane linked
> + * via the CRTC_ID property to the CRTC. At least one CRTC must be included,
> + * and all pulled in CRTCs must be either previously or newly powered on (in
> + * other words, a powered off CRTC which stays off cannot be included in the
> + * atomic commit).
Sounds right. I imagine this doc needs to be extended when drm_colorop
lands, as yet another way to pull in a CRTC.
Wasn't this also conditional on the DRM_CAP_CRTC_IN_VBLANK_EVENT or did
userspace really need to count the events even without it?
Nevertheless, should there be a "see also DRM_CAP_CRTC_IN_VBLANK_EVENT"?
> */
> #define DRM_MODE_PAGE_FLIP_EVENT 0x01
> /**
Thanks,
pq
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