[PATCH] drm/amd/display: Reduce Stack Usage by moving 'audio_output' into 'stream_res'

[Srinivasan Shanmugam]

The function `dp_retrain_link_dp_test` currently allocates a large
audio_output array on the stack, causing the stack frame size to exceed
the compiler limit (1080 bytes > 1024 bytes).

This change prevents stack overflow issues:
amdgpu/../display/dc/link/accessories/link_dp_cts.c:65:13: warning: stack frame size (1080) exceeds limit (1024) in 'dp_retrain_link_dp_test' [-Wframe-larger-than]
static void dp_retrain_link_dp_test(struct dc_link *link,

v2: Move audio-related data like `audio_output` is kept "per pipe" to
    manage the audio for that specific display pipeline/display output path
    (stream). (Wenjing)

'Fixes: 9437059b4bfb ("drm/amd/display: Fix Link Override Sequencing When
Switching Between DIO/HPO")'
Cc: Wayne Lin <wayne.lin at amd.com>
Cc: George Shen <george.shen at amd.com>
Cc: Michael Strauss <michael.strauss at amd.com>
Cc: Alvin Lee <Alvin.Lee2 at amd.com>
Cc: Ray Wu <ray.wu at amd.com>
Cc: Wenjing Liu <wenjing.liu at amd.com>
Cc: Harry Wentland <harry.wentland at amd.com>
Cc: Tom Chung <chiahsuan.chung at amd.com>
Cc: Roman Li <roman.li at amd.com>
Cc: Alex Hung <alex.hung at amd.com>
Cc: Aurabindo Pillai <aurabindo.pillai at amd.com>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam at amd.com>
---
 drivers/gpu/drm/amd/display/dc/inc/core_types.h      |  5 +++--
 .../amd/display/dc/link/accessories/link_dp_cts.c    | 12 ++++++------
 .../amd/display/dc/resource/dcn31/dcn31_resource.c   |  5 ++---
 .../amd/display/dc/resource/dcn31/dcn31_resource.h   |  3 +--
 4 files changed, 12 insertions(+), 13 deletions(-)

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 f0d7185153b2..f896cce87b8d 100644
--- a/drivers/gpu/drm/amd/display/dc/inc/core_types.h
+++ b/drivers/gpu/drm/amd/display/dc/inc/core_types.h
@@ -228,8 +228,7 @@ 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 audio_output *audio_output);
+		struct pipe_ctx *pipes);
 };
 
 struct audio_support{
@@ -361,6 +360,8 @@ 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 2956c2b3ad1a..b12d61701d4d 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
@@ -75,7 +75,6 @@ static void dp_retrain_link_dp_test(struct dc_link *link,
 	bool is_hpo_acquired;
 	uint8_t count;
 	int i;
-	struct audio_output audio_output[MAX_PIPES];
 
 	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));
@@ -99,7 +98,7 @@ 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, &audio_output[0]);
+				*pipes);
 		for (i = 0; i < count; i++) {
 			pipes[i]->clock_source->funcs->program_pix_clk(
 					pipes[i]->clock_source,
@@ -111,15 +110,16 @@ static void dp_retrain_link_dp_test(struct dc_link *link,
 				const struct link_hwss *link_hwss = get_link_hwss(
 					link, &pipes[i]->link_res);
 
-				link_hwss->setup_audio_output(pipes[i], &audio_output[i],
-						pipes[i]->stream_res.audio->inst);
+				link_hwss->setup_audio_output(pipes[i],
+							      &pipes[i]->stream_res.audio_output,
+							      pipes[i]->stream_res.audio->inst);
 
 				pipes[i]->stream_res.audio->funcs->az_configure(
 						pipes[i]->stream_res.audio,
 						pipes[i]->stream->signal,
-						&audio_output[i].crtc_info,
+						&pipes[i]->stream_res.audio_output.crtc_info,
 						&pipes[i]->stream->audio_info,
-						&audio_output[i].dp_link_info);
+						&pipes[i]->stream_res.audio_output.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 3ed7f50554e2..ca17e5d8fdc2 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
@@ -2239,8 +2239,7 @@ 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 audio_output *audio_output)
+	struct pipe_ctx *pipes)
 {
 	struct dc_state *state = link->dc->current_state;
 	int i;
@@ -2255,7 +2254,7 @@ 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], &audio_output[i]);
+			build_audio_output(state, &pipes[i], &pipes[i].stream_res.audio_output);
 	}
 #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 c32c85ef0ba4..7e8fde65528f 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
@@ -69,8 +69,7 @@ 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 audio_output *audio_output);
+	struct pipe_ctx *pipes);
 
 /*temp: B0 specific before switch to dcn313 headers*/
 #ifndef regPHYPLLF_PIXCLK_RESYNC_CNTL
-- 
2.34.1