From: Wayne Lin wayne.lin@amd.com
[ Upstream commit fa57924c76d995e87ca3533ec60d1d5e55769a27 ]
[Why] dm_dp_mst_is_port_support_mode() is a bit not following the original design rule and cause light up issue with multiple 4k monitors after mst dsc hub.
[How] Refactor function dm_dp_mst_is_port_support_mode() a bit to solve the light up issue.
Reviewed-by: Jerry Zuo jerry.zuo@amd.com Acked-by: Zaeem Mohamed zaeem.mohamed@amd.com Signed-off-by: Wayne Lin wayne.lin@amd.com Tested-by: Daniel Wheeler daniel.wheeler@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com [kevin@holm.dev: Resolved merge conflict in .../amdgpu_dm_mst_types.c] Fixes: 4df96ba6676034 ("drm/amd/display: Add timing pixel encoding for mst mode validation") Link: https://lore.kernel.org/stable/d74a7768e957e6ce88c27a5bece0c64dff132e24@holm... Signed-off-by: Kevin Holm kevin@holm.dev --- I resolved the merge conflict so that, after this patch is applied to the linux-6.10.y branch of the stable git repository, the resulting function dm_dp_mst_is_port_support_mode (and also the new function dp_get_link_current_set_bw) is identical to the original commit.
I've confirmed that it fixes the regression I reported for my use case. --- .../display/amdgpu_dm/amdgpu_dm_mst_types.c | 232 +++++++++++------- 1 file changed, 147 insertions(+), 85 deletions(-)
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c index a5e1a93ddaea..e90f9d697511 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c @@ -1595,109 +1595,171 @@ static bool is_dsc_common_config_possible(struct dc_stream_state *stream, return bw_range->max_target_bpp_x16 && bw_range->min_target_bpp_x16; }
+#if defined(CONFIG_DRM_AMD_DC_FP) +static bool dp_get_link_current_set_bw(struct drm_dp_aux *aux, uint32_t *cur_link_bw) +{ + uint32_t total_data_bw_efficiency_x10000 = 0; + uint32_t link_rate_per_lane_kbps = 0; + enum dc_link_rate link_rate; + union lane_count_set lane_count; + u8 dp_link_encoding; + u8 link_bw_set = 0; + + *cur_link_bw = 0; + + if (drm_dp_dpcd_read(aux, DP_MAIN_LINK_CHANNEL_CODING_SET, &dp_link_encoding, 1) != 1 || + drm_dp_dpcd_read(aux, DP_LANE_COUNT_SET, &lane_count.raw, 1) != 1 || + drm_dp_dpcd_read(aux, DP_LINK_BW_SET, &link_bw_set, 1) != 1) + return false; + + switch (dp_link_encoding) { + case DP_8b_10b_ENCODING: + link_rate = link_bw_set; + link_rate_per_lane_kbps = link_rate * LINK_RATE_REF_FREQ_IN_KHZ * BITS_PER_DP_BYTE; + total_data_bw_efficiency_x10000 = DATA_EFFICIENCY_8b_10b_x10000; + total_data_bw_efficiency_x10000 /= 100; + total_data_bw_efficiency_x10000 *= DATA_EFFICIENCY_8b_10b_FEC_EFFICIENCY_x100; + break; + case DP_128b_132b_ENCODING: + switch (link_bw_set) { + case DP_LINK_BW_10: + link_rate = LINK_RATE_UHBR10; + break; + case DP_LINK_BW_13_5: + link_rate = LINK_RATE_UHBR13_5; + break; + case DP_LINK_BW_20: + link_rate = LINK_RATE_UHBR20; + break; + default: + return false; + } + + link_rate_per_lane_kbps = link_rate * 10000; + total_data_bw_efficiency_x10000 = DATA_EFFICIENCY_128b_132b_x10000; + break; + default: + return false; + } + + *cur_link_bw = link_rate_per_lane_kbps * lane_count.bits.LANE_COUNT_SET / 10000 * total_data_bw_efficiency_x10000; + return true; +} +#endif + enum dc_status dm_dp_mst_is_port_support_mode( struct amdgpu_dm_connector *aconnector, struct dc_stream_state *stream) { - int pbn, branch_max_throughput_mps = 0; +#if defined(CONFIG_DRM_AMD_DC_FP) + int branch_max_throughput_mps = 0; struct dc_link_settings cur_link_settings; - unsigned int end_to_end_bw_in_kbps = 0; - unsigned int upper_link_bw_in_kbps = 0, down_link_bw_in_kbps = 0; + uint32_t end_to_end_bw_in_kbps = 0; + uint32_t root_link_bw_in_kbps = 0; + uint32_t virtual_channel_bw_in_kbps = 0; struct dc_dsc_bw_range bw_range = {0}; struct dc_dsc_config_options dsc_options = {0}; + uint32_t stream_kbps;
- /* - * Consider the case with the depth of the mst topology tree is equal or less than 2 - * A. When dsc bitstream can be transmitted along the entire path - * 1. dsc is possible between source and branch/leaf device (common dsc params is possible), AND - * 2. dsc passthrough supported at MST branch, or - * 3. dsc decoding supported at leaf MST device - * Use maximum dsc compression as bw constraint - * B. When dsc bitstream cannot be transmitted along the entire path - * Use native bw as bw constraint + /* DSC unnecessary case + * Check if timing could be supported within end-to-end BW */ - if (is_dsc_common_config_possible(stream, &bw_range) && - (aconnector->mst_output_port->passthrough_aux || - aconnector->dsc_aux == &aconnector->mst_output_port->aux)) { - cur_link_settings = stream->link->verified_link_cap; - upper_link_bw_in_kbps = dc_link_bandwidth_kbps(aconnector->dc_link, &cur_link_settings); - down_link_bw_in_kbps = kbps_from_pbn(aconnector->mst_output_port->full_pbn); - - /* pick the end to end bw bottleneck */ - end_to_end_bw_in_kbps = min(upper_link_bw_in_kbps, down_link_bw_in_kbps); - - if (end_to_end_bw_in_kbps < bw_range.min_kbps) { - DRM_DEBUG_DRIVER("maximum dsc compression cannot fit into end-to-end bandwidth\n"); + stream_kbps = + dc_bandwidth_in_kbps_from_timing(&stream->timing, + dc_link_get_highest_encoding_format(stream->link)); + cur_link_settings = stream->link->verified_link_cap; + root_link_bw_in_kbps = dc_link_bandwidth_kbps(aconnector->dc_link, &cur_link_settings); + virtual_channel_bw_in_kbps = kbps_from_pbn(aconnector->mst_output_port->full_pbn); + + /* pick the end to end bw bottleneck */ + end_to_end_bw_in_kbps = min(root_link_bw_in_kbps, virtual_channel_bw_in_kbps); + + if (stream_kbps <= end_to_end_bw_in_kbps) { + DRM_DEBUG_DRIVER("No DSC needed. End-to-end bw sufficient."); + return DC_OK; + } + + /*DSC necessary case*/ + if (!aconnector->dsc_aux) + return DC_FAIL_BANDWIDTH_VALIDATE; + + if (is_dsc_common_config_possible(stream, &bw_range)) { + + /*capable of dsc passthough. dsc bitstream along the entire path*/ + if (aconnector->mst_output_port->passthrough_aux) { + if (bw_range.min_kbps > end_to_end_bw_in_kbps) { + DRM_DEBUG_DRIVER("DSC passthrough. Max dsc compression can't fit into end-to-end bw\n"); return DC_FAIL_BANDWIDTH_VALIDATE; - } + } + } else { + /*dsc bitstream decoded at the dp last link*/ + struct drm_dp_mst_port *immediate_upstream_port = NULL; + uint32_t end_link_bw = 0; + + /*Get last DP link BW capability*/ + if (dp_get_link_current_set_bw(&aconnector->mst_output_port->aux, &end_link_bw)) { + if (stream_kbps > end_link_bw) { + DRM_DEBUG_DRIVER("DSC decode at last link. Mode required bw can't fit into available bw\n"); + return DC_FAIL_BANDWIDTH_VALIDATE; + } + }
- if (end_to_end_bw_in_kbps < bw_range.stream_kbps) { - dc_dsc_get_default_config_option(stream->link->dc, &dsc_options); - dsc_options.max_target_bpp_limit_override_x16 = aconnector->base.display_info.max_dsc_bpp * 16; - if (dc_dsc_compute_config(stream->sink->ctx->dc->res_pool->dscs[0], - &stream->sink->dsc_caps.dsc_dec_caps, - &dsc_options, - end_to_end_bw_in_kbps, - &stream->timing, - dc_link_get_highest_encoding_format(stream->link), - &stream->timing.dsc_cfg)) { - stream->timing.flags.DSC = 1; - DRM_DEBUG_DRIVER("end-to-end bandwidth require dsc and dsc config found\n"); - } else { - DRM_DEBUG_DRIVER("end-to-end bandwidth require dsc but dsc config not found\n"); - return DC_FAIL_BANDWIDTH_VALIDATE; + /*Get virtual channel bandwidth between source and the link before the last link*/ + if (aconnector->mst_output_port->parent->port_parent) + immediate_upstream_port = aconnector->mst_output_port->parent->port_parent; + + if (immediate_upstream_port) { + virtual_channel_bw_in_kbps = kbps_from_pbn(immediate_upstream_port->full_pbn); + virtual_channel_bw_in_kbps = min(root_link_bw_in_kbps, virtual_channel_bw_in_kbps); + if (bw_range.min_kbps > virtual_channel_bw_in_kbps) { + DRM_DEBUG_DRIVER("DSC decode at last link. Max dsc compression can't fit into MST available bw\n"); + return DC_FAIL_BANDWIDTH_VALIDATE; + } } } - } else { - /* Check if mode could be supported within max slot - * number of current mst link and full_pbn of mst links. - */ - int pbn_div, slot_num, max_slot_num; - enum dc_link_encoding_format link_encoding; - uint32_t stream_kbps = - dc_bandwidth_in_kbps_from_timing(&stream->timing, - dc_link_get_highest_encoding_format(stream->link)); - - pbn = kbps_to_peak_pbn(stream_kbps); - pbn_div = dm_mst_get_pbn_divider(stream->link); - slot_num = DIV_ROUND_UP(pbn, pbn_div); - - link_encoding = dc_link_get_highest_encoding_format(stream->link); - if (link_encoding == DC_LINK_ENCODING_DP_8b_10b) - max_slot_num = 63; - else if (link_encoding == DC_LINK_ENCODING_DP_128b_132b) - max_slot_num = 64; - else { - DRM_DEBUG_DRIVER("Invalid link encoding format\n"); - return DC_FAIL_BANDWIDTH_VALIDATE; - }
- if (slot_num > max_slot_num || - pbn > aconnector->mst_output_port->full_pbn) { - DRM_DEBUG_DRIVER("Mode can not be supported within mst links!"); + /*Confirm if we can obtain dsc config*/ + dc_dsc_get_default_config_option(stream->link->dc, &dsc_options); + dsc_options.max_target_bpp_limit_override_x16 = aconnector->base.display_info.max_dsc_bpp * 16; + if (dc_dsc_compute_config(stream->sink->ctx->dc->res_pool->dscs[0], + &stream->sink->dsc_caps.dsc_dec_caps, + &dsc_options, + end_to_end_bw_in_kbps, + &stream->timing, + dc_link_get_highest_encoding_format(stream->link), + &stream->timing.dsc_cfg)) { + stream->timing.flags.DSC = 1; + DRM_DEBUG_DRIVER("Require dsc and dsc config found\n"); + } else { + DRM_DEBUG_DRIVER("Require dsc but can't find appropriate dsc config\n"); return DC_FAIL_BANDWIDTH_VALIDATE; } - }
- /* check is mst dsc output bandwidth branch_overall_throughput_0_mps */ - switch (stream->timing.pixel_encoding) { - case PIXEL_ENCODING_RGB: - case PIXEL_ENCODING_YCBCR444: - branch_max_throughput_mps = - aconnector->dc_sink->dsc_caps.dsc_dec_caps.branch_overall_throughput_0_mps; - break; - case PIXEL_ENCODING_YCBCR422: - case PIXEL_ENCODING_YCBCR420: - branch_max_throughput_mps = - aconnector->dc_sink->dsc_caps.dsc_dec_caps.branch_overall_throughput_1_mps; - break; - default: - break; - } + /* check is mst dsc output bandwidth branch_overall_throughput_0_mps */ + switch (stream->timing.pixel_encoding) { + case PIXEL_ENCODING_RGB: + case PIXEL_ENCODING_YCBCR444: + branch_max_throughput_mps = + aconnector->dc_sink->dsc_caps.dsc_dec_caps.branch_overall_throughput_0_mps; + break; + case PIXEL_ENCODING_YCBCR422: + case PIXEL_ENCODING_YCBCR420: + branch_max_throughput_mps = + aconnector->dc_sink->dsc_caps.dsc_dec_caps.branch_overall_throughput_1_mps; + break; + default: + break; + }
- if (branch_max_throughput_mps != 0 && - ((stream->timing.pix_clk_100hz / 10) > branch_max_throughput_mps * 1000)) + if (branch_max_throughput_mps != 0 && + ((stream->timing.pix_clk_100hz / 10) > branch_max_throughput_mps * 1000)) { + DRM_DEBUG_DRIVER("DSC is required but max throughput mps fails"); return DC_FAIL_BANDWIDTH_VALIDATE; - + } + } else { + DRM_DEBUG_DRIVER("DSC is required but can't find common dsc config."); + return DC_FAIL_BANDWIDTH_VALIDATE; + } +#endif return DC_OK; }