[PATCH] drm/amd/display: Move 'audio descriptor' storage from 'stream resource' to 'dc scratch'

Liu, Wenjing Wenjing.Liu at amd.com
Fri Aug 1 18:36:09 UTC 2025


[AMD Official Use Only - AMD Internal Distribution Only]

Reviewed-by: Wenjing Liu <wenjing.liu at amd.com>

________________________________
From: SHANMUGAM, SRINIVASAN <SRINIVASAN.SHANMUGAM at amd.com>
Sent: Friday, August 01, 2025 8:12 AM
To: Hung, Alex <Alex.Hung at amd.com>; Pillai, Aurabindo <Aurabindo.Pillai at amd.com>; Lei, Jun <Jun.Lei at amd.com>; Liu, Wenjing <Wenjing.Liu at amd.com>
Cc: amd-gfx at lists.freedesktop.org <amd-gfx at lists.freedesktop.org>; SHANMUGAM, SRINIVASAN <SRINIVASAN.SHANMUGAM at amd.com>; Strauss, Michael <Michael.Strauss at amd.com>; Lee, Alvin <Alvin.Lee2 at amd.com>; LIPSKI, IVAN <IVAN.LIPSKI at amd.com>
Subject: [PATCH] drm/amd/display: Move 'audio descriptor' storage from 'stream resource' to 'dc scratch'

The `stream_resource` structure holds hardware parts and resources that
stay active as long as the display stream or pipe is running. It
represents the hardware state.

The `audio_output` structure is temporary. It is built and used only
during operations like dc validation and link retraining. It does not
represent permanent hardware resources.

This patch moves the audio_output descriptor from stream_res to
dc_scratch_space. This keeps temporary data separate from permanent
hardware state

'Fixes: 571662266db3 ("drm/amd/display: Reduce Stack Usage by moving
'audio_output' into 'stream_res' v4")'
Cc: Michael Strauss <michael.strauss at amd.com>
Cc: Alvin Lee <Alvin.Lee2 at amd.com>
Cc: Jun Lei <Jun.Lei at amd.com>
Cc: Wenjing Liu <wenjing.liu at amd.com>
Cc: Alex Hung <alex.hung at amd.com>
Cc: Ivan Lipski <ivan.lipski at amd.com>
Cc: Aurabindo Pillai <aurabindo.pillai at amd.com>
Suggested-by: Jun Lei <Jun.Lei at amd.com>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam at amd.com>
---
 drivers/gpu/drm/amd/display/dc/dc.h           |  3 ++
 .../amd/display/dc/hwss/dce110/dce110_hwseq.c | 30 +++++++++++--------
 .../gpu/drm/amd/display/dc/inc/core_types.h   |  5 ++--
 .../display/dc/link/accessories/link_dp_cts.c | 13 +++++---
 .../dc/resource/dcn31/dcn31_resource.c        |  5 ++--
 .../dc/resource/dcn31/dcn31_resource.h        |  3 +-
 6 files changed, 36 insertions(+), 23 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/dc.h b/drivers/gpu/drm/amd/display/dc/dc.h
index 5653c1673aec..c6bfde9d3e98 100644
--- a/drivers/gpu/drm/amd/display/dc/dc.h
+++ b/drivers/gpu/drm/amd/display/dc/dc.h
@@ -47,6 +47,7 @@
 #include "dmub/inc/dmub_cmd.h"

 #include "sspl/dc_spl_types.h"
+#include "audio_types.h"

 struct abm_save_restore;

@@ -1734,6 +1735,8 @@ struct dc {
                 struct dc_stream_state temp_stream; // Used so we don't need to allocate stream on the stack
                 struct dc_link temp_link;
                 bool pipes_to_unlock_first[MAX_PIPES]; /* Any of the pipes indicated here should be unlocked first */
+               /* Pre-allocated buffer for audio_output used in dp_retrain_link_dp_test() */
+               struct audio_output audio_output[MAX_PIPES];
         } scratch;

         struct dml2_configuration_options dml2_options;
diff --git a/drivers/gpu/drm/amd/display/dc/hwss/dce110/dce110_hwseq.c b/drivers/gpu/drm/amd/display/dc/hwss/dce110/dce110_hwseq.c
index 153d68375fa3..49ad34734cef 100644
--- a/drivers/gpu/drm/amd/display/dc/hwss/dce110/dce110_hwseq.c
+++ b/drivers/gpu/drm/amd/display/dc/hwss/dce110/dce110_hwseq.c
@@ -1586,6 +1586,7 @@ enum dc_status dce110_apply_single_controller_ctx_to_hw(
                 struct dc_state *context,
                 struct dc *dc)
 {
+       struct audio_output *audio_output;
         struct dc_stream_state *stream = pipe_ctx->stream;
         struct dc_link *link = stream->link;
         struct drr_params params = {0};
@@ -1595,23 +1596,23 @@ enum dc_status dce110_apply_single_controller_ctx_to_hw(
         const struct link_hwss *link_hwss = get_link_hwss(
                         link, &pipe_ctx->link_res);

-
         if (hws->funcs.disable_stream_gating) {
                 hws->funcs.disable_stream_gating(dc, pipe_ctx);
         }

         if (pipe_ctx->stream_res.audio != NULL) {
-               build_audio_output(context, pipe_ctx, &pipe_ctx->stream_res.audio_output);
+               audio_output = &dc->scratch.audio_output[pipe_ctx->pipe_idx];
+               build_audio_output(context, pipe_ctx, audio_output);

-               link_hwss->setup_audio_output(pipe_ctx, &pipe_ctx->stream_res.audio_output,
+               link_hwss->setup_audio_output(pipe_ctx, audio_output,
                                 pipe_ctx->stream_res.audio->inst);

                 pipe_ctx->stream_res.audio->funcs->az_configure(
                                 pipe_ctx->stream_res.audio,
                                 pipe_ctx->stream->signal,
-                               &pipe_ctx->stream_res.audio_output.crtc_info,
+                               &audio_output->crtc_info,
                                 &pipe_ctx->stream->audio_info,
-                               &pipe_ctx->stream_res.audio_output.dp_link_info);
+                               &audio_output->dp_link_info);

                 if (dc->config.disable_hbr_audio_dp2)
                         if (pipe_ctx->stream_res.audio->funcs->az_disable_hbr_audio &&
@@ -2354,6 +2355,7 @@ static void dce110_setup_audio_dto(
                 struct dc_state *context)
 {
         unsigned int i;
+       struct audio_output *audio_output;

         /* program audio wall clock. use HDMI as clock source if HDMI
          * audio active. Otherwise, use DP as clock source
@@ -2385,7 +2387,8 @@ static void dce110_setup_audio_dto(
                 if (pipe_ctx->stream->signal != SIGNAL_TYPE_HDMI_TYPE_A)
                         continue;
                 if (pipe_ctx->stream_res.audio != NULL) {
-                       build_audio_output(context, pipe_ctx, &pipe_ctx->stream_res.audio_output);
+                       audio_output = &dc->scratch.audio_output[i];
+                       build_audio_output(context, pipe_ctx, audio_output);

                         if (dc->res_pool->dccg && dc->res_pool->dccg->funcs->set_audio_dtbclk_dto) {
                                 struct dtbclk_dto_params dto_params = {0};
@@ -2396,14 +2399,14 @@ static void dce110_setup_audio_dto(
                                 pipe_ctx->stream_res.audio->funcs->wall_dto_setup(
                                                 pipe_ctx->stream_res.audio,
                                                 pipe_ctx->stream->signal,
-                                               &pipe_ctx->stream_res.audio_output.crtc_info,
-                                               &pipe_ctx->stream_res.audio_output.pll_info);
+                                               &audio_output->crtc_info,
+                                               &audio_output->pll_info);
                         } else
                                 pipe_ctx->stream_res.audio->funcs->wall_dto_setup(
                                         pipe_ctx->stream_res.audio,
                                         pipe_ctx->stream->signal,
-                                       &pipe_ctx->stream_res.audio_output.crtc_info,
-                                       &pipe_ctx->stream_res.audio_output.pll_info);
+                                       &audio_output->crtc_info,
+                                       &audio_output->pll_info);
                         break;
                 }
         }
@@ -2423,15 +2426,16 @@ static void dce110_setup_audio_dto(
                                 continue;

                         if (pipe_ctx->stream_res.audio != NULL) {
+                               audio_output = &dc->scratch.audio_output[i];
                                 build_audio_output(context,
                                                    pipe_ctx,
-                                                  &pipe_ctx->stream_res.audio_output);
+                                                  audio_output);

                                 pipe_ctx->stream_res.audio->funcs->wall_dto_setup(
                                         pipe_ctx->stream_res.audio,
                                         pipe_ctx->stream->signal,
-                                       &pipe_ctx->stream_res.audio_output.crtc_info,
-                                       &pipe_ctx->stream_res.audio_output.pll_info);
+                                       &audio_output->crtc_info,
+                                       &audio_output->pll_info);
                                 break;
                         }
                 }
diff --git a/drivers/gpu/drm/amd/display/dc/inc/core_types.h b/drivers/gpu/drm/amd/display/dc/inc/core_types.h
index 4387de044469..df0d72b2c1b0 100644
--- a/drivers/gpu/drm/amd/display/dc/inc/core_types.h
+++ b/drivers/gpu/drm/amd/display/dc/inc/core_types.h
@@ -228,7 +228,8 @@ struct resource_funcs {
         enum dc_status (*update_dc_state_for_encoder_switch)(struct dc_link *link,
                 struct dc_link_settings *link_setting,
                 uint8_t pipe_count,
-               struct pipe_ctx *pipes);
+               struct pipe_ctx *pipes,
+               struct audio_output *audio_output);
 };

 struct audio_support{
@@ -360,8 +361,6 @@ struct stream_resource {
         uint8_t gsl_group;

         struct test_pattern_params test_pattern_params;
-
-       struct audio_output audio_output;
 };

 struct plane_resource {
diff --git a/drivers/gpu/drm/amd/display/dc/link/accessories/link_dp_cts.c b/drivers/gpu/drm/amd/display/dc/link/accessories/link_dp_cts.c
index 23f41c99fa38..4af5fde2e392 100644
--- a/drivers/gpu/drm/amd/display/dc/link/accessories/link_dp_cts.c
+++ b/drivers/gpu/drm/amd/display/dc/link/accessories/link_dp_cts.c
@@ -35,6 +35,7 @@
 #include "dc_dmub_srv.h"
 #include "dce/dmub_hw_lock_mgr.h"
 #include "clk_mgr.h"
+#include "dc.h"

 #define DC_LOGGER \
         link->ctx->logger
@@ -66,6 +67,7 @@ static void dp_retrain_link_dp_test(struct dc_link *link,
                         struct dc_link_settings *link_setting,
                         bool skip_video_pattern)
 {
+       struct dc *dc = (struct dc *)(unsigned long)link->dc;
         struct pipe_ctx *pipes[MAX_PIPES];
         struct dc_state *state = link->dc->current_state;
         struct dc_stream_update stream_update = { 0 };
@@ -79,6 +81,9 @@ static void dp_retrain_link_dp_test(struct dc_link *link,
         struct dc_stream_state *streams_on_link[MAX_PIPES];
         int num_streams_on_link = 0;

+       /* Zero out the scratch audio output array */
+       memset((void *)dc->scratch.audio_output, 0, sizeof(dc->scratch.audio_output));
+
         needs_divider_update = (link->dc->link_srv->dp_get_encoding_format(link_setting) !=
         link->dc->link_srv->dp_get_encoding_format((const struct dc_link_settings *) &link->cur_link_settings));

@@ -101,7 +106,7 @@ static void dp_retrain_link_dp_test(struct dc_link *link,
         if (needs_divider_update && link->dc->res_pool->funcs->update_dc_state_for_encoder_switch) {
                 link->dc->res_pool->funcs->update_dc_state_for_encoder_switch(link,
                                 link_setting, count,
-                               *pipes);
+                               *pipes, dc->scratch.audio_output);
                 for (i = 0; i < count; i++) {
                         pipes[i]->clock_source->funcs->program_pix_clk(
                                         pipes[i]->clock_source,
@@ -114,15 +119,15 @@ static void dp_retrain_link_dp_test(struct dc_link *link,
                                         link, &pipes[i]->link_res);

                                 link_hwss->setup_audio_output(pipes[i],
-                                                             &pipes[i]->stream_res.audio_output,
+                                                             &dc->scratch.audio_output[i],
                                                               pipes[i]->stream_res.audio->inst);

                                 pipes[i]->stream_res.audio->funcs->az_configure(
                                                 pipes[i]->stream_res.audio,
                                                 pipes[i]->stream->signal,
-                                               &pipes[i]->stream_res.audio_output.crtc_info,
+                                               &dc->scratch.audio_output[i].crtc_info,
                                                 &pipes[i]->stream->audio_info,
-                                               &pipes[i]->stream_res.audio_output.dp_link_info);
+                                               &dc->scratch.audio_output[i].dp_link_info);

                                 if (link->dc->config.disable_hbr_audio_dp2 &&
                                                 pipes[i]->stream_res.audio->funcs->az_disable_hbr_audio &&
diff --git a/drivers/gpu/drm/amd/display/dc/resource/dcn31/dcn31_resource.c b/drivers/gpu/drm/amd/display/dc/resource/dcn31/dcn31_resource.c
index ca17e5d8fdc2..3ed7f50554e2 100644
--- a/drivers/gpu/drm/amd/display/dc/resource/dcn31/dcn31_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/resource/dcn31/dcn31_resource.c
@@ -2239,7 +2239,8 @@ struct resource_pool *dcn31_create_resource_pool(
 enum dc_status dcn31_update_dc_state_for_encoder_switch(struct dc_link *link,
         struct dc_link_settings *link_setting,
         uint8_t pipe_count,
-       struct pipe_ctx *pipes)
+       struct pipe_ctx *pipes,
+       struct audio_output *audio_output)
 {
         struct dc_state *state = link->dc->current_state;
         int i;
@@ -2254,7 +2255,7 @@ enum dc_status dcn31_update_dc_state_for_encoder_switch(struct dc_link *link,

                 // Setup audio
                 if (pipes[i].stream_res.audio != NULL)
-                       build_audio_output(state, &pipes[i], &pipes[i].stream_res.audio_output);
+                       build_audio_output(state, &pipes[i], &audio_output[i]);
         }
 #else
         /* This DCN requires rate divider updates and audio reprogramming to allow DP1<-->DP2 link rate switching,
diff --git a/drivers/gpu/drm/amd/display/dc/resource/dcn31/dcn31_resource.h b/drivers/gpu/drm/amd/display/dc/resource/dcn31/dcn31_resource.h
index 7e8fde65528f..c32c85ef0ba4 100644
--- a/drivers/gpu/drm/amd/display/dc/resource/dcn31/dcn31_resource.h
+++ b/drivers/gpu/drm/amd/display/dc/resource/dcn31/dcn31_resource.h
@@ -69,7 +69,8 @@ unsigned int dcn31_get_det_buffer_size(
 enum dc_status dcn31_update_dc_state_for_encoder_switch(struct dc_link *link,
         struct dc_link_settings *link_setting,
         uint8_t pipe_count,
-       struct pipe_ctx *pipes);
+       struct pipe_ctx *pipes,
+       struct audio_output *audio_output);

 /*temp: B0 specific before switch to dcn313 headers*/
 #ifndef regPHYPLLF_PIXCLK_RESYNC_CNTL
--
2.34.1

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