Hi Tomi, On Tuesday 13 Dec 2016 09:58:34 Tomi Valkeinen wrote: > On 13/12/16 00:53, Laurent Pinchart wrote: > > On Tuesday 20 Sep 2016 16:51:11 Tomi Valkeinen wrote: > >> On 19/09/16 15:27, Laurent Pinchart wrote: > >>> The DRM core supports skipping plane update for inactive CRTCs for > >>> hardware that don't need it or can't cope with it. That's our case, so > >>> use the DRM core infrastructure instead of reinventing it. > >> > >> I don't follow this desc. What is omapdrm reinventing? At least this > >> patch does not remove any of the "reinvention". > > > > There used to be one, but it got removed when I rebased the patch series. > > I'll reword the commit message. > > > >> What does DRM_PLANE_COMMIT_ACTIVE_ONLY do? Skips plane HW configuration > >> for planes on crtcs that are disabled? The plane HW config will still be > >> done when the crtc is about to be enabled, right? > > > > It skips plane update (atomic_begin, atomic_disable, atomic_flush) for > > disabled CRTCs. The CRTC .begin() operation is still called for those > > CRTCs, only plane update is skipped. > > I didn't catch that. Skips atomic_begin, but .begin is still called? Sorry, I meant .disable(). > > Now that I wrote that, I'm not quite sure this change is right. It looks > > like disabling a plane is shadowed, and without an atomic_flush call the > > GO bit will never be set. However, the problem predates this patch, as > > the GO bit will only be set if dispc_mgr_is_enabled() returns true, which > > shouldn't be the case for disabled CRTCs. > > > > How is this supposed to work, how is plane disable supposed to be > > synchronized at the hardware level ? > > If a crtc is currently disabled (in the HW), all the new settings > (including plane enable/disable bit) can be programmed and when the crtc > is enabled, those settings are taken into use. GO bit is not necessary. > > When the crtc is active, you need to set the GO bit to get the new > settings into use at next vblank. > > If a crtc is to be disabled, we can just disable the crtc, GO bit is not > necessary. Thanks for the clarification. -- Regards, Laurent Pinchart _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
