drm/amd/display: Add debug messages for dc_validate_boot_timing()

dc_validate_boot_timing() runs through an exhaustive list of checks to
determine whether a boot stream can be marked as seamless. When the
checks fail, a user will be left guessing what the reason was

Add debug statements that will be helpful to validate the specific
reason.

Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Link: https://lore.kernel.org/r/20250120194903.1048811-1-superm1@kernel.org
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc.c b/drivers/gpu/drm/amd/display/dc/core/dc.c
index edf7e3b52b28d13b720e8fc23d0dbbc0f99d2bc3..ba3a34fad26a68f976ab10c463b870ece2ee3cdb 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/core/dc.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc.c
@@ -1720,17 +1720,23 @@ bool dc_validate_boot_timing(const struct dc *dc,
                return false;
        }
 
-       if (dc->debug.force_odm_combine)
+       if (dc->debug.force_odm_combine) {
+               DC_LOG_DEBUG("boot timing validation failed due to force_odm_combine\n");
                return false;
+       }
 
        /* Check for enabled DIG to identify enabled display */
-       if (!link->link_enc->funcs->is_dig_enabled(link->link_enc))
+       if (!link->link_enc->funcs->is_dig_enabled(link->link_enc)) {
+               DC_LOG_DEBUG("boot timing validation failed due to disabled DIG\n");
                return false;
+       }
 
        enc_inst = link->link_enc->funcs->get_dig_frontend(link->link_enc);
 
-       if (enc_inst == ENGINE_ID_UNKNOWN)
+       if (enc_inst == ENGINE_ID_UNKNOWN) {
+               DC_LOG_DEBUG("boot timing validation failed due to unknown DIG engine ID\n");
                return false;
+       }
 
        for (i = 0; i < dc->res_pool->stream_enc_count; i++) {
                if (dc->res_pool->stream_enc[i]->id == enc_inst) {
@@ -1744,62 +1750,98 @@ bool dc_validate_boot_timing(const struct dc *dc,
        }
 
        // tg_inst not found
-       if (i == dc->res_pool->stream_enc_count)
+       if (i == dc->res_pool->stream_enc_count) {
+               DC_LOG_DEBUG("boot timing validation failed due to timing generator instance not found\n");
                return false;
+       }
 
-       if (tg_inst >= dc->res_pool->timing_generator_count)
+       if (tg_inst >= dc->res_pool->timing_generator_count) {
+               DC_LOG_DEBUG("boot timing validation failed due to invalid timing generator count\n");
                return false;
+       }
 
-       if (tg_inst != link->link_enc->preferred_engine)
+       if (tg_inst != link->link_enc->preferred_engine) {
+               DC_LOG_DEBUG("boot timing validation failed due to non-preferred timing generator\n");
                return false;
+       }
 
        tg = dc->res_pool->timing_generators[tg_inst];
 
-       if (!tg->funcs->get_hw_timing)
+       if (!tg->funcs->get_hw_timing) {
+               DC_LOG_DEBUG("boot timing validation failed due to missing get_hw_timing callback\n");
                return false;
+       }
 
-       if (!tg->funcs->get_hw_timing(tg, &hw_crtc_timing))
+       if (!tg->funcs->get_hw_timing(tg, &hw_crtc_timing)) {
+               DC_LOG_DEBUG("boot timing validation failed due to failed get_hw_timing return\n");
                return false;
+       }
 
-       if (crtc_timing->h_total != hw_crtc_timing.h_total)
+       if (crtc_timing->h_total != hw_crtc_timing.h_total) {
+               DC_LOG_DEBUG("boot timing validation failed due to h_total mismatch\n");
                return false;
+       }
 
-       if (crtc_timing->h_border_left != hw_crtc_timing.h_border_left)
+       if (crtc_timing->h_border_left != hw_crtc_timing.h_border_left) {
+               DC_LOG_DEBUG("boot timing validation failed due to h_border_left mismatch\n");
                return false;
+       }
 
-       if (crtc_timing->h_addressable != hw_crtc_timing.h_addressable)
+       if (crtc_timing->h_addressable != hw_crtc_timing.h_addressable) {
+               DC_LOG_DEBUG("boot timing validation failed due to h_addressable mismatch\n");
                return false;
+       }
 
-       if (crtc_timing->h_border_right != hw_crtc_timing.h_border_right)
+       if (crtc_timing->h_border_right != hw_crtc_timing.h_border_right) {
+               DC_LOG_DEBUG("boot timing validation failed due to h_border_right mismatch\n");
                return false;
+       }
 
-       if (crtc_timing->h_front_porch != hw_crtc_timing.h_front_porch)
+       if (crtc_timing->h_front_porch != hw_crtc_timing.h_front_porch) {
+               DC_LOG_DEBUG("boot timing validation failed due to h_front_porch mismatch\n");
                return false;
+       }
 
-       if (crtc_timing->h_sync_width != hw_crtc_timing.h_sync_width)
+       if (crtc_timing->h_sync_width != hw_crtc_timing.h_sync_width) {
+               DC_LOG_DEBUG("boot timing validation failed due to h_sync_width mismatch\n");
                return false;
+       }
 
-       if (crtc_timing->v_total != hw_crtc_timing.v_total)
+       if (crtc_timing->v_total != hw_crtc_timing.v_total) {
+               DC_LOG_DEBUG("boot timing validation failed due to v_total mismatch\n");
                return false;
+       }
 
-       if (crtc_timing->v_border_top != hw_crtc_timing.v_border_top)
+       if (crtc_timing->v_border_top != hw_crtc_timing.v_border_top) {
+               DC_LOG_DEBUG("boot timing validation failed due to v_border_top mismatch\n");
                return false;
+       }
 
-       if (crtc_timing->v_addressable != hw_crtc_timing.v_addressable)
+       if (crtc_timing->v_addressable != hw_crtc_timing.v_addressable) {
+               DC_LOG_DEBUG("boot timing validation failed due to v_addressable mismatch\n");
                return false;
+       }
 
-       if (crtc_timing->v_border_bottom != hw_crtc_timing.v_border_bottom)
+       if (crtc_timing->v_border_bottom != hw_crtc_timing.v_border_bottom) {
+               DC_LOG_DEBUG("boot timing validation failed due to v_border_bottom mismatch\n");
                return false;
+       }
 
-       if (crtc_timing->v_front_porch != hw_crtc_timing.v_front_porch)
+       if (crtc_timing->v_front_porch != hw_crtc_timing.v_front_porch) {
+               DC_LOG_DEBUG("boot timing validation failed due to v_front_porch mismatch\n");
                return false;
+       }
 
-       if (crtc_timing->v_sync_width != hw_crtc_timing.v_sync_width)
+       if (crtc_timing->v_sync_width != hw_crtc_timing.v_sync_width) {
+               DC_LOG_DEBUG("boot timing validation failed due to v_sync_width mismatch\n");
                return false;
+       }
 
        /* block DSC for now, as VBIOS does not currently support DSC timings */
-       if (crtc_timing->flags.DSC)
+       if (crtc_timing->flags.DSC) {
+               DC_LOG_DEBUG("boot timing validation failed due to DSC\n");
                return false;
+       }
 
        if (dc_is_dp_signal(link->connector_signal)) {
                unsigned int pix_clk_100hz = 0;
@@ -1821,39 +1863,55 @@ bool dc_validate_boot_timing(const struct dc *dc,
                } else if (se && se->funcs->get_pixels_per_cycle) {
                        uint32_t pixels_per_cycle = se->funcs->get_pixels_per_cycle(se);
 
-                       if (pixels_per_cycle != 1 && !dc->debug.enable_dp_dig_pixel_rate_div_policy)
+                       if (pixels_per_cycle != 1 && !dc->debug.enable_dp_dig_pixel_rate_div_policy) {
+                               pr_info("boot timing validation failed due to pixels_per_cycle\n");
                                return false;
+                       }
 
                        pix_clk_100hz *= pixels_per_cycle;
                }
 
                // Note: In rare cases, HW pixclk may differ from crtc's pixclk
                // slightly due to rounding issues in 10 kHz units.
-               if (crtc_timing->pix_clk_100hz != pix_clk_100hz)
+               if (crtc_timing->pix_clk_100hz != pix_clk_100hz) {
+                       DC_LOG_DEBUG("boot timing validation failed due to pix_clk_100hz mismatch\n");
                        return false;
+               }
 
-               if (!se || !se->funcs->dp_get_pixel_format)
+               if (!se || !se->funcs->dp_get_pixel_format) {
+                       DC_LOG_DEBUG("boot timing validation failed due to missing dp_get_pixel_format\n");
                        return false;
+               }
 
                if (!se->funcs->dp_get_pixel_format(
                        se,
                        &hw_crtc_timing.pixel_encoding,
-                       &hw_crtc_timing.display_color_depth))
+                       &hw_crtc_timing.display_color_depth)) {
+                       DC_LOG_DEBUG("boot timing validation failed due to dp_get_pixel_format failure\n");
                        return false;
+               }
 
-               if (hw_crtc_timing.display_color_depth != crtc_timing->display_color_depth)
+               if (hw_crtc_timing.display_color_depth != crtc_timing->display_color_depth) {
+                       DC_LOG_DEBUG("boot timing validation failed due to display_color_depth mismatch\n");
                        return false;
+               }
 
-               if (hw_crtc_timing.pixel_encoding != crtc_timing->pixel_encoding)
+               if (hw_crtc_timing.pixel_encoding != crtc_timing->pixel_encoding) {
+                       DC_LOG_DEBUG("boot timing validation failed due to pixel_encoding mismatch\n");
                        return false;
+               }
        }
 
+
        if (link->dpcd_caps.dprx_feature.bits.VSC_SDP_COLORIMETRY_SUPPORTED) {
+               DC_LOG_DEBUG("boot timing validation failed due to VSC SDP colorimetry\n");
                return false;
        }
 
-       if (link->dpcd_caps.channel_coding_cap.bits.DP_128b_132b_SUPPORTED)
+       if (link->dpcd_caps.channel_coding_cap.bits.DP_128b_132b_SUPPORTED) {
+               DC_LOG_DEBUG("boot timing validation failed due to DP 128b/132b\n");
                return false;
+       }
 
        if (dc->link_srv->edp_is_ilr_optimization_required(link, crtc_timing)) {
                DC_LOG_EVENT_LINK_TRAINING("Seamless boot disabled to optimize eDP link rate\n");