On Thu, 13 Feb 2020, Matt Roper <matthew.d.roper@xxxxxxxxx> wrote: > On Thu, Feb 13, 2020 at 11:03:29PM +0200, Jani Nikula wrote: >> On Thu, 13 Feb 2020, Matt Roper <matthew.d.roper@xxxxxxxxx> wrote: >> > On Thu, Feb 13, 2020 at 04:04:11PM +0200, Stanislav Lisovskiy wrote: >> >> From: Jani Nikula <jani.nikula@xxxxxxxxx> >> >> >> >> We lack full state readout of DSC config, which may lead to DSC enable >> >> using a config that's all zeros, failing spectacularly. Force full >> >> modeset and thus compute config at probe to get a sane state, until we >> >> implement DSC state readout. Any fastset that did appear to work with >> >> DSC at probe, worked by coincidence. [1] is an example of a change that >> >> triggered the issue on TGL DSI DSC. >> >> >> >> [1] http://patchwork.freedesktop.org/patch/msgid/20200212150102.7600-1-ville.syrjala@xxxxxxxxxxxxxxx >> >> >> >> Cc: Manasi Navare <manasi.d.navare@xxxxxxxxx> >> >> Cc: Vandita Kulkarni <vandita.kulkarni@xxxxxxxxx> >> >> Cc: Ville Syrjala <ville.syrjala@xxxxxxxxxxxxxxx> >> >> Cc: stable@xxxxxxxxxxxxxxx >> >> Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx> >> > >> > Should this be >> > >> > Fixes: fbacb15ea814 ("drm/i915/dsc: add basic hardware state readout support") >> > >> > since that's where we added the basic readout with a FIXME to add more >> > later? >> >> That added some readout and checks, but the problem existed before them >> too. > > Right, but that's as far back as we can go with a fix, right? Since > before that we don't even read out enough to know that compression is > enabled? Ah, that's right. Any fixes predating that commit would have to be different. Perhaps we'll just settle for this. ;) Thanks, Jani. > > > Matt > >> >> BR, >> Jani. >> >> >> >> > >> > I don't know the specifics of DSC and what state we need, but the >> > approach here seems reasonable. >> > >> > Acked-by: Matt Roper <matthew.d.roper@xxxxxxxxx> >> > >> >> --- >> >> drivers/gpu/drm/i915/display/intel_display.c | 18 ++++++++++++++++++ >> >> 1 file changed, 18 insertions(+) >> >> >> >> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c >> >> index 61ba1f2256a0..1e3f2cc27db8 100644 >> >> --- a/drivers/gpu/drm/i915/display/intel_display.c >> >> +++ b/drivers/gpu/drm/i915/display/intel_display.c >> >> @@ -17828,6 +17828,24 @@ static int intel_initial_commit(struct drm_device *dev) >> >> * have readout for pipe gamma enable. >> >> */ >> >> crtc_state->uapi.color_mgmt_changed = true; >> >> + >> >> + /* >> >> + * FIXME hack to force full modeset when DSC is being >> >> + * used. >> >> + * >> >> + * As long as we do not have full state readout and >> >> + * config comparison of crtc_state->dsc, we have no way >> >> + * to ensure reliable fastset. Remove once we have >> >> + * readout for DSC. >> >> + */ >> >> + if (crtc_state->dsc.compression_enable) { >> >> + ret = drm_atomic_add_affected_connectors(state, >> >> + &crtc->base); >> >> + if (ret) >> >> + goto out; >> >> + crtc_state->uapi.mode_changed = true; >> >> + drm_dbg_kms(dev, "Force full modeset for DSC\n"); >> >> + } >> >> } >> >> } >> >> >> >> -- >> >> 2.24.1.485.gad05a3d8e5 >> >> >> >> _______________________________________________ >> >> Intel-gfx mailing list >> >> Intel-gfx@xxxxxxxxxxxxxxxxxxxxx >> >> https://lists.freedesktop.org/mailman/listinfo/intel-gfx >> >> -- >> Jani Nikula, Intel Open Source Graphics Center -- Jani Nikula, Intel Open Source Graphics Center _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
