drm/amd/display: avoid large stack allocation in commit_planes_do_stream_update_sequence

The function has two arrays on the stack to hold temporary dsc_optc_config
and dsc_config objects. The combination blows through common stack frame
warning limits in combination with the other local variables:

drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc.c:4070:22: error: stack frame size (1352) exceeds limit
      (1280) in 'commit_planes_do_stream_update_sequence' [-Werror,-Wframe-larger-than]

Since neither array is initialized or used outside of the
add_link_update_dsc_config_sequence() function, there is no actual
need to keep each element around.

Replace the arrays with a single instance each to reduce the stack usage
to less than half.

Fixes: 9f49d3cd7e71 ("drm/amd/display: Implement block sequencing infrastructure for modular hardware operations.")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Tested-by: Dan Wheeler <daniel.wheeler@amd.com>
Acked-by: George Zhang <george.zhang@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 0e3c27d526c320a261c2296c8280b38a5672a550..0ecb025e76facd34ffb25ec5934ac0974f8f159a 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/core/dc.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc.c
@@ -4128,8 +4128,6 @@ static void commit_planes_do_stream_update_sequence(struct dc *dc,
 {
        int j;
        struct block_sequence_state seq_state = { .steps = block_sequence, .num_steps = num_steps };
-       struct dsc_config dsc_cfgs[MAX_PIPES];
-       struct dsc_optc_config dsc_optc_cfgs[MAX_PIPES];
        unsigned int dsc_cfg_index = 0;
        *num_steps = 0; // Initialize to 0
 
@@ -4201,11 +4199,13 @@ static void commit_planes_do_stream_update_sequence(struct dc *dc,
 
                        if (stream_update->dsc_config)
                                if (dsc_cfg_index < MAX_PIPES) {
+                                       struct dsc_config dsc_cfg;
+                                       struct dsc_optc_config dsc_optc_cfg;
+
                                        add_link_update_dsc_config_sequence(&seq_state,
                                                pipe_ctx,
-                                               &dsc_cfgs[dsc_cfg_index],
-                                               &dsc_optc_cfgs[dsc_cfg_index]);
-                                       dsc_cfg_index++;
+                                               &dsc_cfg,
+                                               &dsc_optc_cfg);
                                }
 
                        if (stream_update->mst_bw_update) {