drm/amd/display: Destroy DC context while keeping DML and DML2

If there is memory pressure at suspend time then dynamically
allocating a large structure as part of DC suspend code will
fail.

Instead re-use the same structures and clear all members except
those that should be maintained.

Link: https://gitlab.freedesktop.org/drm/amd/-/issues/2362
Acked-by: Alex Deucher <alexander.deucher@amd.com>
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 074a692..fd35ab2 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/core/dc.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc.c
@@ -4781,12 +4781,6 @@ bool dc_set_power_state(
        struct dc *dc,
        enum dc_acpi_cm_power_state power_state)
 {
-       struct kref refcount;
-       struct display_mode_lib *dml;
-#ifdef CONFIG_DRM_AMD_DC_FP
-       struct dml2_context *dml2 = NULL;
-#endif
-
        if (!dc->current_state)
                return true;
 
@@ -4805,40 +4799,9 @@ bool dc_set_power_state(
 
                break;
        default:
-#ifdef CONFIG_DRM_AMD_DC_FP
-               if (dc->debug.using_dml2)
-                       dml2 = dc->current_state->bw_ctx.dml2;
-#endif
                ASSERT(dc->current_state->stream_count == 0);
-               /* Zero out the current context so that on resume we start with
-                * clean state, and dc hw programming optimizations will not
-                * cause any trouble.
-                */
-               dml = kzalloc(sizeof(struct display_mode_lib),
-                               GFP_KERNEL);
-
-               ASSERT(dml);
-               if (!dml)
-                       return false;
-
-               /* Preserve refcount */
-               refcount = dc->current_state->refcount;
-               /* Preserve display mode lib */
-               memcpy(dml, &dc->current_state->bw_ctx.dml, sizeof(struct display_mode_lib));
 
                dc_resource_state_destruct(dc->current_state);
-               memset(dc->current_state, 0,
-                               sizeof(*dc->current_state));
-
-               dc->current_state->refcount = refcount;
-               dc->current_state->bw_ctx.dml = *dml;
-
-               kfree(dml);
-
-#ifdef CONFIG_DRM_AMD_DC_FP
-               if (dc->debug.using_dml2)
-                       dc->current_state->bw_ctx.dml2 = dml2;
-#endif
 
                break;
        }

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_resource.c b/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
index 25562b2..a7e49c7 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
@@ -4487,6 +4487,18 @@ void dc_resource_state_destruct(struct dc_state *context)
                context->streams[i] = NULL;
        }
        context->stream_count = 0;
+       context->stream_mask = 0;
+       memset(&context->res_ctx, 0, sizeof(context->res_ctx));
+       memset(&context->pp_display_cfg, 0, sizeof(context->pp_display_cfg));
+       memset(&context->dcn_bw_vars, 0, sizeof(context->dcn_bw_vars));
+       context->clk_mgr = NULL;
+       memset(&context->bw_ctx.bw, 0, sizeof(context->bw_ctx.bw));
+       memset(context->block_sequence, 0, sizeof(context->block_sequence));
+       context->block_sequence_steps = 0;
+       memset(context->dc_dmub_cmd, 0, sizeof(context->dc_dmub_cmd));
+       context->dmub_cmd_count = 0;
+       memset(&context->perf_params, 0, sizeof(context->perf_params));
+       memset(&context->scratch, 0, sizeof(context->scratch));
 }
 
 void dc_resource_state_copy_construct(