From: Stanislav Lisovskiy <stanislav.lisovs...@intel.com> Currently we seem to be using wrong DPCD register for reading compressed bpps, reading min/max input bpc instead of compressed bpp. Fix that, so that we now apply min/max compressed bpp limitations we get from DP Spec Table 2-157 DP v2.0 and/or correspondent DPCD register DP_DSC_MAX_BITS_PER_PIXEL_LOW/HIGH.
This might also allow us to get rid of an ugly compressed bpp recalculation, which we had to add to make some MST hubs usable. v2: - Fix operator precedence v3: - Added debug info about compressed bpps v4: - Don't try to intersect Sink input bpp and compressed bpps. v5: - Decrease step while looking for suitable compressed bpp to accommodate. v6: - Use helper for getting min and max compressed_bpp (Ankit) v7: - Fix checkpatch warning (Ankit) Signed-off-by: Stanislav Lisovskiy <stanislav.lisovs...@intel.com> Signed-off-by: Ankit Nautiyal <ankit.k.nauti...@intel.com> --- drivers/gpu/drm/i915/display/intel_dp.c | 14 +++--- drivers/gpu/drm/i915/display/intel_dp.h | 4 ++ drivers/gpu/drm/i915/display/intel_dp_mst.c | 47 +++++++++------------ 3 files changed, 32 insertions(+), 33 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c index 25a6c162332f..ce8b28ca1cfa 100644 --- a/drivers/gpu/drm/i915/display/intel_dp.c +++ b/drivers/gpu/drm/i915/display/intel_dp.c @@ -1762,7 +1762,7 @@ u16 intel_dp_dsc_max_sink_compressed_bppx16(struct intel_dp *intel_dp, return 0; } -static int dsc_sink_min_compressed_bpp(struct intel_crtc_state *pipe_config) +int intel_dp_dsc_sink_min_compressed_bpp(struct intel_crtc_state *pipe_config) { /* From Mandatory bit rate range Support Table 2-157 (DP v2.0) */ switch (pipe_config->output_format) { @@ -1779,9 +1779,9 @@ static int dsc_sink_min_compressed_bpp(struct intel_crtc_state *pipe_config) return 0; } -static int dsc_sink_max_compressed_bpp(struct intel_dp *intel_dp, - struct intel_crtc_state *pipe_config, - int bpc) +int intel_dp_dsc_sink_max_compressed_bpp(struct intel_dp *intel_dp, + struct intel_crtc_state *pipe_config, + int bpc) { return intel_dp_dsc_max_sink_compressed_bppx16(intel_dp, pipe_config, bpc) >> 4; @@ -1894,11 +1894,13 @@ static int dsc_compute_compressed_bpp(struct intel_dp *intel_dp, int dsc_joiner_max_bpp; dsc_src_min_bpp = dsc_src_min_compressed_bpp(); - dsc_sink_min_bpp = dsc_sink_min_compressed_bpp(pipe_config); + dsc_sink_min_bpp = intel_dp_dsc_sink_min_compressed_bpp(pipe_config); dsc_min_bpp = max(dsc_src_min_bpp, dsc_sink_min_bpp); dsc_src_max_bpp = dsc_src_max_compressed_bpp(intel_dp); - dsc_sink_max_bpp = dsc_sink_max_compressed_bpp(intel_dp, pipe_config, pipe_bpp / 3); + dsc_sink_max_bpp = intel_dp_dsc_sink_max_compressed_bpp(intel_dp, + pipe_config, + pipe_bpp / 3); dsc_max_bpp = dsc_sink_max_bpp ? min(dsc_sink_max_bpp, dsc_src_max_bpp) : dsc_src_max_bpp; dsc_joiner_max_bpp = get_max_compressed_bpp_with_joiner(i915, adjusted_mode->clock, diff --git a/drivers/gpu/drm/i915/display/intel_dp.h b/drivers/gpu/drm/i915/display/intel_dp.h index 788a577ebe16..f29e48028f39 100644 --- a/drivers/gpu/drm/i915/display/intel_dp.h +++ b/drivers/gpu/drm/i915/display/intel_dp.h @@ -114,6 +114,10 @@ u16 intel_dp_dsc_get_max_compressed_bpp(struct drm_i915_private *i915, enum intel_output_format output_format, u32 pipe_bpp, u32 timeslots); +int intel_dp_dsc_sink_min_compressed_bpp(struct intel_crtc_state *pipe_config); +int intel_dp_dsc_sink_max_compressed_bpp(struct intel_dp *intel_dp, + struct intel_crtc_state *pipe_config, + int bpc); u8 intel_dp_dsc_get_slice_count(struct intel_dp *intel_dp, int mode_clock, int mode_hdisplay, bool bigjoiner); diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c index 3eb085fbc7c8..06a456517383 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c @@ -101,6 +101,9 @@ static int intel_dp_mst_find_vcpi_slots_for_bpp(struct intel_encoder *encoder, crtc_state->lane_count); } + drm_dbg_kms(&i915->drm, "Looking for slots in range min bpp %d max bpp %d\n", + min_bpp, max_bpp); + for (bpp = max_bpp; bpp >= min_bpp; bpp -= step) { drm_dbg_kms(&i915->drm, "Trying bpp %d\n", bpp); @@ -194,8 +197,7 @@ static int intel_dp_dsc_mst_compute_link_config(struct intel_encoder *encoder, u8 dsc_bpc[3] = {0}; int min_bpp, max_bpp, sink_min_bpp, sink_max_bpp; u8 dsc_max_bpc; - bool need_timeslot_recalc = false; - u32 last_compressed_bpp; + int min_compressed_bpp, max_compressed_bpp; /* Max DSC Input BPC for ICL is 10 and for TGL+ is 12 */ if (DISPLAY_VER(i915) >= 12) @@ -231,34 +233,25 @@ static int intel_dp_dsc_mst_compute_link_config(struct intel_encoder *encoder, if (max_bpp > sink_max_bpp) max_bpp = sink_max_bpp; - slots = intel_dp_mst_find_vcpi_slots_for_bpp(encoder, crtc_state, max_bpp, - min_bpp, limits, - conn_state, 2 * 3, true); - - if (slots < 0) - return slots; - - last_compressed_bpp = crtc_state->dsc.compressed_bpp; + max_compressed_bpp = intel_dp_dsc_sink_max_compressed_bpp(intel_dp, + crtc_state, + max_bpp / 3); + min_compressed_bpp = intel_dp_dsc_sink_min_compressed_bpp(crtc_state); + drm_dbg_kms(&i915->drm, "DSC Sink supported compressed min bpp %d compressed max bpp %d\n", + min_compressed_bpp, max_compressed_bpp); - crtc_state->dsc.compressed_bpp = intel_dp_dsc_nearest_valid_bpp(i915, - last_compressed_bpp, - crtc_state->pipe_bpp); + /* Align compressed bpps according to our own constraints */ + max_compressed_bpp = intel_dp_dsc_nearest_valid_bpp(i915, max_compressed_bpp, + crtc_state->pipe_bpp); + min_compressed_bpp = intel_dp_dsc_nearest_valid_bpp(i915, min_compressed_bpp, + crtc_state->pipe_bpp); - if (crtc_state->dsc.compressed_bpp != last_compressed_bpp) - need_timeslot_recalc = true; + slots = intel_dp_mst_find_vcpi_slots_for_bpp(encoder, crtc_state, max_compressed_bpp, + min_compressed_bpp, limits, + conn_state, 1, true); - /* - * Apparently some MST hubs dislike if vcpi slots are not matching precisely - * the actual compressed bpp we use. - */ - if (need_timeslot_recalc) { - slots = intel_dp_mst_find_vcpi_slots_for_bpp(encoder, crtc_state, - crtc_state->dsc.compressed_bpp, - crtc_state->dsc.compressed_bpp, - limits, conn_state, 2 * 3, true); - if (slots < 0) - return slots; - } + if (slots < 0) + return slots; intel_link_compute_m_n(crtc_state->dsc.compressed_bpp, crtc_state->lane_count, -- 2.40.1