Hi Maxime,
W dniu 13.10.2022 o 15:19, Maxime Ripard pisze:
> From: Mateusz Kwiatkowski > > The VEC can accept pretty much any relatively
> reasonable mode, but still > has a bunch of constraints to meet. > > Let's
> create an atomic_check() implementation that will make sure we > don't end up
> accepting a non-functional mode. > > Acked-by: Noralf Trønnes >
> Signed-off-by: Mateusz Kwiatkowski > Signed-off-by: Maxime Ripard > --- >
> drivers/gpu/drm/vc4/vc4_vec.c | 48
> +++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 48
> insertions(+) > > diff --git a/drivers/gpu/drm/vc4/vc4_vec.c
> b/drivers/gpu/drm/vc4/vc4_vec.c > index 90e375a8a8f9..1fcb7baf874e 100644 >
> --- a/drivers/gpu/drm/vc4/vc4_vec.c > +++ b/drivers/gpu/drm/vc4/vc4_vec.c >
> @@ -453,6 +453,7 @@ static int vc4_vec_encoder_atomic_check(struct
> drm_encoder *encoder, > struct drm_crtc_state *crtc_state, > struct
> drm_connector_state *conn_state) > { > + const struct drm_display_mode *mode
> = &crtc_state->adjusted_mode; > const struct vc4_vec_tv_mode *vec_mode; > >
> vec_mode =
&vc4_vec_tv_modes[conn_state->tv.legacy_mode]; > @@ -461,6 +462,53 @@ static
int vc4_vec_encoder_atomic_check(struct drm_encoder *encoder, >
!drm_mode_equal(vec_mode->mode, &crtc_state->adjusted_mode)) > return -EINVAL;
> > + if (mode->crtc_hdisplay % 4) > + return -EINVAL; > + > + if
(!(mode->crtc_hsync_end - mode->crtc_hsync_start)) > + return -EINVAL; > + > +
switch (mode->vtotal) { > + case 525: > + if (mode->crtc_vtotal > 262) > +
return -EINVAL; > + > + if (mode->crtc_vdisplay < 1 || mode->crtc_vdisplay >
253) > + return -EINVAL; > + > + if (!(mode->crtc_vsync_start -
mode->crtc_vdisplay)) > + return -EINVAL; > + > + if ((mode->crtc_vsync_end -
mode->crtc_vsync_start) != 3) > + return -EINVAL; > + > + if
((mode->crtc_vtotal - mode->crtc_vsync_end) < 4) > + return -EINVAL; > + > +
break; > + > + case 625: > + if (mode->crtc_vtotal > 312) > + return -EINVAL; >
+ > + if (mode->crtc_vdisplay < 1 || mode->crtc_vdisplay > 305) > + return
-EINVAL; > + > + if
(!(mode->crtc_vsync_start - mode->crtc_vdisplay)) > + return -EINVAL; > + > +
if ((mode->crtc_vsync_end - mode->crtc_vsync_start) != 3) > + return -EINVAL; >
+ > + if ((mode->crtc_vtotal - mode->crtc_vsync_end) < 2) > + return -EINVAL; >
+ > + break; > + > + default: > + return -EINVAL; > + } > + > return 0; > } In
my original version of this function
(https://github.com/raspberrypi/linux/pull/4406/files) the switch is over
reference_mode->vtotal, not mode->vtotal. This was intended to explicitly allow
a different value of mode->vtotal, to support non-standard modes, such as
"fake" 525 lines with SECAM encoding, or the progressive modes. You're
switching over mode->vtotal, which makes specifying those impossible. I don't
think we should limit the users like that. We're removing reference_mode in
patch 20/22, so adding a switch over reference_mode->vtotal is probably not a
good idea -- in that case I'd switch over mode->htotal instead: 858 for "NTSC"
and 864 for "PAL". This
may seem a bit weird, but any other value of htotal causes the VEC to output
garbage anyway. Best regards, Mateusz Kwiatkowski
