Hi,
> -----Original Message-----
> From: Intel-gfx <intel-gfx-bounces@xxxxxxxxxxxxxxxxxxxxx> On Behalf Of Jani
> Nikula
> Sent: Tuesday, 4 February 2025 18.40
> To: Deak, Imre <imre.deak@xxxxxxxxx>
> Cc: intel-gfx@xxxxxxxxxxxxxxxxxxxxx; intel-xe@xxxxxxxxxxxxxxxxxxxxx
> Subject: Re: [PATCH] drm/i915/dp: Add support for DP UHBR SST DSC
>
> On Tue, 04 Feb 2025, Imre Deak <imre.deak@xxxxxxxxx> wrote:
> > On Mon, Feb 03, 2025 at 06:08:34PM +0200, Jani Nikula wrote:
> >> Drop the UHBR limitation from DP SST DSC, and handle SST DSC
> >> bandwidth computation for UHBR using
> intel_dp_mtp_tu_compute_config().
> >>
> >> Cc: Imre Deak <imre.deak@xxxxxxxxx>
> >> Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx>
> >
> > Reviewed-by: Imre Deak <imre.deak@xxxxxxxxx>
> >
> > With the DPT bpp and bpp_step fixes on the list, this seems to work on
> > a
> > DP2.0 dock on (SST) UHBR link/DSC mode.
>
> \o/
>
> Thanks for the review and testing!
Awesome, thanks Jani N and Imre!
> >
Br,
Jani
> >> ---
> >> drivers/gpu/drm/i915/display/intel_dp.c | 35
> >> +++++++++++++++++++------
> >> 1 file changed, 27 insertions(+), 8 deletions(-)
> >>
> >> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c
> >> b/drivers/gpu/drm/i915/display/intel_dp.c
> >> index cc6aba353c11..eb8f6806166c 100644
> >> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> >> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> >> @@ -1958,15 +1958,37 @@ static int dsc_compute_link_config(struct
> intel_dp *intel_dp,
> >> for (lane_count = limits->min_lane_count;
> >> lane_count <= limits->max_lane_count;
> >> lane_count <<= 1) {
> >> - if (!is_bw_sufficient_for_dsc_config(dsc_bpp_x16,
> link_rate,
> >> - lane_count,
> adjusted_mode->clock,
> >> - pipe_config-
> >output_format,
> >> - timeslots))
> >> - continue;
> >>
> >> + /*
> >> + * FIXME: intel_dp_mtp_tu_compute_config()
> requires
> >> + * ->lane_count and ->port_clock set before we know
> >> + * they'll work. If we end up failing altogether,
> >> + * they'll remain in crtc state. This shouldn't matter,
> >> + * as we'd then bail out from compute config, but it's
> >> + * just ugly.
> >> + */
> >> pipe_config->lane_count = lane_count;
> >> pipe_config->port_clock = link_rate;
> >>
> >> + if (drm_dp_is_uhbr_rate(link_rate)) {
> >> + int ret;
> >> +
> >> + ret =
> intel_dp_mtp_tu_compute_config(intel_dp,
> >> +
> pipe_config,
> >> + conn_state,
> >> +
> dsc_bpp_x16,
> >> +
> dsc_bpp_x16,
> >> + 0, true);
> >> + if (ret)
> >> + continue;
> >> + } else {
> >> + if
> (!is_bw_sufficient_for_dsc_config(dsc_bpp_x16, link_rate,
> >> + lane_count,
> adjusted_mode->clock,
> >> +
> pipe_config->output_format,
> >> + timeslots))
> >> + continue;
> >> + }
> >> +
> >> return 0;
> >> }
> >> }
> >> @@ -2493,9 +2515,6 @@ intel_dp_compute_config_limits(struct intel_dp
> *intel_dp,
> >> limits->min_rate = intel_dp_min_link_rate(intel_dp);
> >> limits->max_rate = intel_dp_max_link_rate(intel_dp);
> >>
> >> - /* FIXME 128b/132b SST+DSC support missing */
> >> - if (!is_mst && dsc)
> >> - limits->max_rate = min(limits->max_rate, 810000);
> >> limits->min_rate = min(limits->min_rate, limits->max_rate);
> >>
> >> limits->min_lane_count = intel_dp_min_lane_count(intel_dp);
> >> --
> >> 2.39.5
> >>
>
> --
> Jani Nikula, Intel
