On Mon, Apr 09, 2018 at 05:12:03PM +0300, Jani Nikula wrote:
> On Thu, 05 Apr 2018, Manasi Navare <manasi.d.navare@xxxxxxxxx> wrote:
> > On Thu, Apr 05, 2018 at 05:39:04PM +0300, Jani Nikula wrote:
> >> For now, there's just the one link config selection, optimizing for slow
> >> and wide link. No functional changes.
> >>
> >> Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx>
> >> ---
> >> drivers/gpu/drm/i915/intel_dp.c | 81 +++++++++++++++++++++++++----------------
> >> 1 file changed, 50 insertions(+), 31 deletions(-)
> >>
> >> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> >> index 3c5fbdf42b9b..c98626b3af65 100644
> >> --- a/drivers/gpu/drm/i915/intel_dp.c
> >> +++ b/drivers/gpu/drm/i915/intel_dp.c
> >> @@ -1704,6 +1704,42 @@ static bool intel_edp_compare_alt_mode(struct drm_display_mode *m1,
> >> return bres;
> >> }
> >>
> >> +/* Optimize link config in order: max bpp, min clock, min lanes */
> >> +static bool
> >> +intel_dp_compute_link_config_wide(struct intel_dp *intel_dp,
> >> + struct intel_crtc_state *pipe_config,
> >> + const struct link_config_limits *limits)
> >> +{
> >> + struct drm_display_mode *adjusted_mode = &pipe_config->base.adjusted_mode;
> >> + int bpp, clock, lane_count;
> >> + int mode_rate, link_clock, link_avail;
> >> +
> >> + for (bpp = limits->max_bpp; bpp >= limits->min_bpp; bpp -= 2 * 3) {
> >> + mode_rate = intel_dp_link_required(adjusted_mode->crtc_clock,
> >> + bpp);
> >> +
> >> + for (clock = limits->min_clock; clock <= limits->max_clock; clock++) {
> >> + for (lane_count = limits->min_lane_count;
> >> + lane_count <= limits->max_lane_count;
> >> + lane_count <<= 1) {
> >> + link_clock = intel_dp->common_rates[clock];
> >> + link_avail = intel_dp_max_data_rate(link_clock,
> >> + lane_count);
> >> +
> >> + if (mode_rate <= link_avail) {
> >> + pipe_config->lane_count = lane_count;
> >> + pipe_config->pipe_bpp = bpp;
> >> + pipe_config->port_clock = link_clock;
> >> +
> >> + return true;
> >> + }
> >> + }
> >> + }
> >> + }
> >> +
> >> + return false;
> >> +}
> >> +
> >> static bool
> >> intel_dp_compute_link_config(struct intel_encoder *encoder,
> >> struct intel_crtc_state *pipe_config)
> >> @@ -1711,8 +1747,6 @@ intel_dp_compute_link_config(struct intel_encoder *encoder,
> >> struct drm_display_mode *adjusted_mode = &pipe_config->base.adjusted_mode;
> >> struct intel_dp *intel_dp = enc_to_intel_dp(&encoder->base);
> >> struct link_config_limits limits;
> >> - int bpp, clock, lane_count;
> >> - int mode_rate, link_avail, link_clock;
> >> int common_len;
> >>
> >> common_len = intel_dp_common_len_rate_limit(intel_dp,
> >> @@ -1766,37 +1800,22 @@ intel_dp_compute_link_config(struct intel_encoder *encoder,
> >> intel_dp->common_rates[limits.max_clock],
> >> limits.max_bpp, adjusted_mode->crtc_clock);
> >>
> >> - for (bpp = limits.max_bpp; bpp >= limits.min_bpp; bpp -= 2 * 3) {
> >> - mode_rate = intel_dp_link_required(adjusted_mode->crtc_clock,
> >> - bpp);
> >> -
> >> - for (clock = limits.min_clock; clock <= limits.max_clock; clock++) {
> >> - for (lane_count = limits.min_lane_count;
> >> - lane_count <= limits.max_lane_count;
> >> - lane_count <<= 1) {
> >> -
> >> - link_clock = intel_dp->common_rates[clock];
> >> - link_avail = intel_dp_max_data_rate(link_clock,
> >> - lane_count);
> >> -
> >> - if (mode_rate <= link_avail) {
> >> - goto found;
> >> - }
> >> - }
> >> - }
> >> - }
> >> -
> >> - return false;
> >> -
> >> -found:
> >> - pipe_config->lane_count = lane_count;
> >> - pipe_config->pipe_bpp = bpp;
> >> - pipe_config->port_clock = intel_dp->common_rates[clock];
> >> + /*
> >> + * Optimize for slow and wide. This is the place to add alternative
> >> + * optimization policy.
> >> + */
> >> + if (!intel_dp_compute_link_config_wide(intel_dp, pipe_config, &limits))
> >> + return false;
> >>
> >> DRM_DEBUG_KMS("DP lane count %d clock %d bpp %d\n",
> >> - pipe_config->lane_count, pipe_config->port_clock, bpp);
> >> - DRM_DEBUG_KMS("DP link bw required %i available %i\n",
> >> - mode_rate, link_avail);
> >> + pipe_config->lane_count, pipe_config->port_clock,
> >> + pipe_config->pipe_bpp);
> >> +
> >> + DRM_DEBUG_KMS("DP link rate required %i available %i\n",
> >> + intel_dp_link_required(adjusted_mode->crtc_clock,
> >> + pipe_config->pipe_bpp),
> >> + intel_dp_max_data_rate(pipe_config->port_clock,
> >> + pipe_config->lane_count));
> >
> > Wouldnt it be better if we move this Debug message about Available and
> > required link rate in the other function right after the condition
> > if (mode_rate <= link_avail) is true, before returning true from that function.
> > I think it will be just more intuitive there.
>
> That's what I thought too at first, but then realized if we're going to
> add an alternative call to an alternative approach, and perhaps yet
> another for DSC, the debugging gets duplicated in all of them.
>
> BR,
> Jani.
Yes that makes sense then to have the debug messages outside in the main compute_config function.
Thanks for the clarification. So with that:
Reviewed-by: Manasi Navare <manasi.d.navare@xxxxxxxxx>
Manasi
>
>
> >
> > Everything else looks good. So
> >
> > Reviewed-by: Manasi Navare <manasi.d.navare@xxxxxxxxx>
> >
> > Manasi
> >
> >>
> >> return true;
> >> }
> >> --
> >> 2.11.0
> >>
> > _______________________________________________
> > Intel-gfx mailing list
> > Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
> > https://lists.freedesktop.org/mailman/listinfo/intel-gfx
>
> --
> Jani Nikula, Intel Open Source Technology Center
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