On 12/02/2020 15:59, Jyri Sarha wrote: > The old implementation of placing planes on the CRTC while configuring > the planes was naive and relied on the order in which the planes were > configured, enabled, and disabled. The situation where a plane's zpos > was changed on the fly was completely broken. The usual symptoms of > this problem was scrambled display and a flood of sync lost errors, > when a plane was active in two layers at the same time, or a missing > plane, in case when a layer was accidentally disabled. > > The rewrite takes a more straight forward approach when HW is > concerned. The plane positioning registers are in the CRTC (actually > OVR) register space and it is more natural to configure them in one go > while configuring the CRTC. To do this we need to make sure we have > all the planes on updated CRTCs in the new atomic state to be > committed. This is done by calling drm_atomic_add_affected_planes() in > crtc_atomic_check(). > > Signed-off-by: Jyri Sarha <jsa...@ti.com> > --- > drivers/gpu/drm/tidss/tidss_crtc.c | 55 ++++++++++++++++++++++++++++- > drivers/gpu/drm/tidss/tidss_dispc.c | 55 +++++++++++------------------ > drivers/gpu/drm/tidss/tidss_dispc.h | 5 +++ > 3 files changed, 79 insertions(+), 36 deletions(-) > > diff --git a/drivers/gpu/drm/tidss/tidss_crtc.c > b/drivers/gpu/drm/tidss/tidss_crtc.c > index 032c31ee2820..f7c5fd1094a8 100644 > --- a/drivers/gpu/drm/tidss/tidss_crtc.c > +++ b/drivers/gpu/drm/tidss/tidss_crtc.c ... > @@ -108,7 +110,54 @@ static int tidss_crtc_atomic_check(struct drm_crtc *crtc, > return -EINVAL; > } > > - return dispc_vp_bus_check(dispc, hw_videoport, state); > + ret = dispc_vp_bus_check(dispc, hw_videoport, state); > + if (ret) > + return ret; > + > + /* Add unchanged planes on this crtc to state for zpos update. */ > + return drm_atomic_add_affected_planes(state->state, crtc);
Is this a correct way to use drm_atomic_add_affected_planes()? I saw that some other drivers implement their own mode_config atomic_check() and have this call there in for_each_new_crtc_in_state()-loop, but I thought it should be fine to call it in crtc_atomic_check(). BR, Jyri -- Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel
