drm/amd/display: dsc validate fail not pass to atomic check

[Why] when 4k@144hz dp connect to dp1.4 dsc mst hub, requested
bandwidth exceeds caps of dsc hub. but dsc bw valid functions,
increase_dsc_bpp, try_disable_dsc, pre_validate_dsc,
compute_mst_dsc_configs_for_state, do not return false to
atomic check. this cause user mode initiate mode set to kernel,
then cause kernel assert, system hang.

[How] dsc bandwidth valid functions return pass or fail to atomic
check.

Reviewed-by: Wayne Lin <Wayne.Lin@amd.com>
Reviewed-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Acked-by: Hamza Mahfooz <hamza.mahfooz@amd.com>
Signed-off-by: hersen wu <hersenxs.wu@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index 4a90ee111aec9a3781932f61f3ee9f10567ffd4b..60fb99b7471310c5705cb0baac940413e0aee944 100644 (file)
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -11255,7 +11255,10 @@ static int amdgpu_dm_atomic_check(struct drm_device *dev,
                                }
                        }
                }
-               pre_validate_dsc(state, &dm_state, vars);
+               if (!pre_validate_dsc(state, &dm_state, vars)) {
+                       ret = -EINVAL;
+                       goto fail;
+               }
        }
 #endif
        for_each_oldnew_crtc_in_state(state, crtc, old_crtc_state, new_crtc_state, i) {
@@ -11501,6 +11504,7 @@ static int amdgpu_dm_atomic_check(struct drm_device *dev,
 #if defined(CONFIG_DRM_AMD_DC_DCN)
                if (!compute_mst_dsc_configs_for_state(state, dm_state->context, vars)) {
                        DRM_DEBUG_DRIVER("compute_mst_dsc_configs_for_state() failed\n");
+                       ret = -EINVAL;
                        goto fail;
                }
 

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
index a6d551ff89d1f0e8f06f62a303744f7c8bcb7de3..7e246a798c8a419149d4b057bd61762875711576 100644 (file)
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
@@ -670,7 +670,7 @@ static int bpp_x16_from_pbn(struct dsc_mst_fairness_params param, int pbn)
        return dsc_config.bits_per_pixel;
 }
 
-static void increase_dsc_bpp(struct drm_atomic_state *state,
+static bool increase_dsc_bpp(struct drm_atomic_state *state,
                             struct dc_link *dc_link,
                             struct dsc_mst_fairness_params *params,
                             struct dsc_mst_fairness_vars *vars,
@@ -730,7 +730,7 @@ static void increase_dsc_bpp(struct drm_atomic_state *state,
                                                          params[next_index].port,
                                                          vars[next_index].pbn,
                                                          pbn_per_timeslot) < 0)
-                               return;
+                               return false;
                        if (!drm_dp_mst_atomic_check(state)) {
                                vars[next_index].bpp_x16 = bpp_x16_from_pbn(params[next_index], vars[next_index].pbn);
                        } else {
@@ -740,7 +740,7 @@ static void increase_dsc_bpp(struct drm_atomic_state *state,
                                                                  params[next_index].port,
                                                                  vars[next_index].pbn,
                                                                  pbn_per_timeslot) < 0)
-                                       return;
+                                       return false;
                        }
                } else {
                        vars[next_index].pbn += initial_slack[next_index];
@@ -749,7 +749,7 @@ static void increase_dsc_bpp(struct drm_atomic_state *state,
                                                          params[next_index].port,
                                                          vars[next_index].pbn,
                                                          pbn_per_timeslot) < 0)
-                               return;
+                               return false;
                        if (!drm_dp_mst_atomic_check(state)) {
                                vars[next_index].bpp_x16 = params[next_index].bw_range.max_target_bpp_x16;
                        } else {
@@ -759,16 +759,17 @@ static void increase_dsc_bpp(struct drm_atomic_state *state,
                                                                  params[next_index].port,
                                                                  vars[next_index].pbn,
                                                                  pbn_per_timeslot) < 0)
-                                       return;
+                                       return false;
                        }
                }
 
                bpp_increased[next_index] = true;
                remaining_to_increase--;
        }
+       return true;
 }
 
-static void try_disable_dsc(struct drm_atomic_state *state,
+static bool try_disable_dsc(struct drm_atomic_state *state,
                            struct dc_link *dc_link,
                            struct dsc_mst_fairness_params *params,
                            struct dsc_mst_fairness_vars *vars,
@@ -816,7 +817,7 @@ static void try_disable_dsc(struct drm_atomic_state *state,
                                                  params[next_index].port,
                                                  vars[next_index].pbn,
                                                  dm_mst_get_pbn_divider(dc_link)) < 0)
-                       return;
+                       return false;
 
                if (!drm_dp_mst_atomic_check(state)) {
                        vars[next_index].dsc_enabled = false;
@@ -828,12 +829,13 @@ static void try_disable_dsc(struct drm_atomic_state *state,
                                                          params[next_index].port,
                                                          vars[next_index].pbn,
                                                          dm_mst_get_pbn_divider(dc_link)) < 0)
-                               return;
+                               return false;
                }
 
                tried[next_index] = true;
                remaining_to_try--;
        }
+       return true;
 }
 
 static bool compute_mst_dsc_configs_for_link(struct drm_atomic_state *state,
@@ -949,9 +951,11 @@ static bool compute_mst_dsc_configs_for_link(struct drm_atomic_state *state,
                return false;
 
        /* Optimize degree of compression */
-       increase_dsc_bpp(state, dc_link, params, vars, count, k);
+       if (!increase_dsc_bpp(state, dc_link, params, vars, count, k))
+               return false;
 
-       try_disable_dsc(state, dc_link, params, vars, count, k);
+       if (!try_disable_dsc(state, dc_link, params, vars, count, k))
+               return false;
 
        set_dsc_configs_from_fairness_vars(params, vars, count, k);
 
@@ -1223,21 +1227,22 @@ static bool is_dsc_precompute_needed(struct drm_atomic_state *state)
        return ret;
 }
 
-void pre_validate_dsc(struct drm_atomic_state *state,
+bool pre_validate_dsc(struct drm_atomic_state *state,
                      struct dm_atomic_state **dm_state_ptr,
                      struct dsc_mst_fairness_vars *vars)
 {
        int i;
        struct dm_atomic_state *dm_state;
        struct dc_state *local_dc_state = NULL;
+       int ret = 0;
 
        if (!is_dsc_precompute_needed(state)) {
                DRM_INFO_ONCE("DSC precompute is not needed.\n");
-               return;
+               return true;
        }
        if (dm_atomic_get_state(state, dm_state_ptr)) {
                DRM_INFO_ONCE("dm_atomic_get_state() failed\n");
-               return;
+               return false;
        }
        dm_state = *dm_state_ptr;
 
@@ -1249,7 +1254,7 @@ void pre_validate_dsc(struct drm_atomic_state *state,
 
        local_dc_state = kmemdup(dm_state->context, sizeof(struct dc_state), GFP_KERNEL);
        if (!local_dc_state)
-               return;
+               return false;
 
        for (i = 0; i < local_dc_state->stream_count; i++) {
                struct dc_stream_state *stream = dm_state->context->streams[i];
@@ -1275,11 +1280,19 @@ void pre_validate_dsc(struct drm_atomic_state *state,
                                                                &state->crtcs[ind].new_state->mode,
                                                                dm_new_conn_state,
                                                                dm_old_crtc_state->stream);
+                       if (local_dc_state->streams[i] == NULL) {
+                               ret = -EINVAL;
+                               break;
+                       }
                }
        }
 
+       if (ret != 0)
+               goto clean_exit;
+
        if (!pre_compute_mst_dsc_configs_for_state(state, local_dc_state, vars)) {
                DRM_INFO_ONCE("pre_compute_mst_dsc_configs_for_state() failed\n");
+               ret = -EINVAL;
                goto clean_exit;
        }
 
@@ -1309,5 +1322,7 @@ clean_exit:
        }
 
        kfree(local_dc_state);
+
+       return (ret == 0);
 }
 #endif

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.h b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.h
index 85628ad59e6c1a492f0306e515562884ab8b1274..2e13027d9b8843b57fa82a5f013cba46f0426441 100644 (file)
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.h
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.h
@@ -59,7 +59,7 @@ bool compute_mst_dsc_configs_for_state(struct drm_atomic_state *state,
 
 bool needs_dsc_aux_workaround(struct dc_link *link);
 
-void pre_validate_dsc(struct drm_atomic_state *state,
+bool pre_validate_dsc(struct drm_atomic_state *state,
                      struct dm_atomic_state **dm_state_ptr,
                      struct dsc_mst_fairness_vars *vars);