Le lun. 29 mars 2021 à 17:35, Maxime Ripard maxime@cerno.tech a écrit :
On Mon, Mar 29, 2021 at 04:15:28PM +0100, Paul Cercueil wrote:
Hi Maxime,
Le lun. 29 mars 2021 à 16:07, Maxime Ripard maxime@cerno.tech a écrit :
On Sat, Mar 27, 2021 at 11:22:14AM +0000, Paul Cercueil wrote:
The ingenic-drm driver has two mutually exclusive primary
planes
already; so the fact that a CRTC must have one and only one
primary
plane is an invalid assumption.
I mean, no? It's been documented for a while that a CRTC should
only
have a single primary, so I'd say that the invalid assumption was
that
it was possible to have multiple primary planes for a CRTC.
Documented where?
I did read the doc of "enum drm_plane_type" in <drm/drm_plane.h>, and the DRM_PLANE_TYPE_PRIMARY describes my two planes, so I went with that.
At least since 4.9, this was in the documentation generated for DRM: https://elixir.bootlin.com/linux/v4.9.263/source/drivers/gpu/drm/drm_plane.c...
Ok, I read that as "all drivers should provide AT LEAST one primary plane per CRTC", and not as "all drivers should provide ONE AND ONLY ONE primary plane per CRTC". My bad.
-Paul