The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 6513104ba4a808de07722ef4ffb960f0229752b4 Mon Sep 17 00:00:00 2001
From: Hersen Wu hersenwu@amd.com Date: Wed, 25 Aug 2021 16:27:47 -0400 Subject: [PATCH] drm/amd/display: dsc mst 2 4K displays go dark with 2 lane HBR3
[Why] call stack of amdgpu dsc mst pbn, slot num calculation is as below: -compute_bpp_x16_from_target_bandwidth -decide_dsc_target_bpp_x16 -setup_dsc_config -dc_dsc_compute_bandwidth_range -compute_mst_dsc_configs_for_link -compute_mst_dsc_configs_for_state
from pbn -> dsc target bpp_x16
bpp_x16 is calulated by compute_bpp_x16_from_target_bandwidth. Beside pixel clock and bpp, num_slices_h and bpp_increment_div will also affect bpp_x16.
from dsc target bpp_x16 -> pbn
within dm_update_mst_vcpi_slots_for_dsc, pbn = drm_dp_calc_pbn_mode(clock, bpp_x16, true);
drm_dp_calc_pbn_mode(int clock, int bpp, bool dsc) { return DIV_ROUND_UP_ULL(mul_u32_u32(clock * (bpp / 16), 64 * 1006), 8 * 54 * 1000 * 1000); }
bpp / 16 trunc digits after decimal point. This will cause calculation delta. drm_dp_calc_pbn_mode does not have other informations, like num_slices_h, bpp_increment_div. therefore, it does not do revese calcuation properly from bpp_x16 to pbn.
pbn from drm_dp_calc_pbn_mode is less than pbn from compute_mst_dsc_configs_for_state. This cause not enough mst slot allocated to display. display could not visually light up.
[How] pass pbn from compute_mst_dsc_configs_for_state to dm_update_mst_vcpi_slots_for_dsc
Cc: stable@vger.kernel.org
Reviewed-by: Scott Foster Scott.Foster@amd.com Acked-by: Mikita Lipski mikita.lipski@amd.com Signed-off-by: Hersen Wu hersenwu@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 283d660a0a66..24cd4c819e99 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -7092,14 +7092,15 @@ const struct drm_encoder_helper_funcs amdgpu_dm_encoder_helper_funcs = {
#if defined(CONFIG_DRM_AMD_DC_DCN) static int dm_update_mst_vcpi_slots_for_dsc(struct drm_atomic_state *state, - struct dc_state *dc_state) + struct dc_state *dc_state, + struct dsc_mst_fairness_vars *vars) { struct dc_stream_state *stream = NULL; struct drm_connector *connector; struct drm_connector_state *new_con_state; struct amdgpu_dm_connector *aconnector; struct dm_connector_state *dm_conn_state; - int i, j, clock, bpp; + int i, j, clock; int vcpi, pbn_div, pbn = 0;
for_each_new_connector_in_state(state, connector, new_con_state, i) { @@ -7138,9 +7139,15 @@ static int dm_update_mst_vcpi_slots_for_dsc(struct drm_atomic_state *state, }
pbn_div = dm_mst_get_pbn_divider(stream->link); - bpp = stream->timing.dsc_cfg.bits_per_pixel; clock = stream->timing.pix_clk_100hz / 10; - pbn = drm_dp_calc_pbn_mode(clock, bpp, true); + /* pbn is calculated by compute_mst_dsc_configs_for_state*/ + for (j = 0; j < dc_state->stream_count; j++) { + if (vars[j].aconnector == aconnector) { + pbn = vars[j].pbn; + break; + } + } + vcpi = drm_dp_mst_atomic_enable_dsc(state, aconnector->port, pbn, pbn_div, @@ -10546,6 +10553,9 @@ static int amdgpu_dm_atomic_check(struct drm_device *dev, int ret, i; bool lock_and_validation_needed = false; struct dm_crtc_state *dm_old_crtc_state; +#if defined(CONFIG_DRM_AMD_DC_DCN) + struct dsc_mst_fairness_vars vars[MAX_PIPES]; +#endif
trace_amdgpu_dm_atomic_check_begin(state);
@@ -10776,10 +10786,10 @@ static int amdgpu_dm_atomic_check(struct drm_device *dev, goto fail;
#if defined(CONFIG_DRM_AMD_DC_DCN) - if (!compute_mst_dsc_configs_for_state(state, dm_state->context)) + if (!compute_mst_dsc_configs_for_state(state, dm_state->context, vars)) goto fail;
- ret = dm_update_mst_vcpi_slots_for_dsc(state, dm_state->context); + ret = dm_update_mst_vcpi_slots_for_dsc(state, dm_state->context, vars); if (ret) goto fail; #endif 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 705f2e67edb5..1a99fcc27078 100644 --- 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 @@ -518,12 +518,7 @@ struct dsc_mst_fairness_params { uint32_t num_slices_h; uint32_t num_slices_v; uint32_t bpp_overwrite; -}; - -struct dsc_mst_fairness_vars { - int pbn; - bool dsc_enabled; - int bpp_x16; + struct amdgpu_dm_connector *aconnector; };
static int kbps_to_peak_pbn(int kbps) @@ -750,12 +745,12 @@ static void try_disable_dsc(struct drm_atomic_state *state,
static bool compute_mst_dsc_configs_for_link(struct drm_atomic_state *state, struct dc_state *dc_state, - struct dc_link *dc_link) + struct dc_link *dc_link, + struct dsc_mst_fairness_vars *vars) { int i; struct dc_stream_state *stream; struct dsc_mst_fairness_params params[MAX_PIPES]; - struct dsc_mst_fairness_vars vars[MAX_PIPES]; struct amdgpu_dm_connector *aconnector; int count = 0; bool debugfs_overwrite = false; @@ -776,6 +771,7 @@ static bool compute_mst_dsc_configs_for_link(struct drm_atomic_state *state, params[count].timing = &stream->timing; params[count].sink = stream->sink; aconnector = (struct amdgpu_dm_connector *)stream->dm_stream_context; + params[count].aconnector = aconnector; params[count].port = aconnector->port; params[count].clock_force_enable = aconnector->dsc_settings.dsc_force_enable; if (params[count].clock_force_enable == DSC_CLK_FORCE_ENABLE) @@ -798,6 +794,7 @@ static bool compute_mst_dsc_configs_for_link(struct drm_atomic_state *state, } /* Try no compression */ for (i = 0; i < count; i++) { + vars[i].aconnector = params[i].aconnector; vars[i].pbn = kbps_to_peak_pbn(params[i].bw_range.stream_kbps); vars[i].dsc_enabled = false; vars[i].bpp_x16 = 0; @@ -851,7 +848,8 @@ static bool compute_mst_dsc_configs_for_link(struct drm_atomic_state *state, }
bool compute_mst_dsc_configs_for_state(struct drm_atomic_state *state, - struct dc_state *dc_state) + struct dc_state *dc_state, + struct dsc_mst_fairness_vars *vars) { int i, j; struct dc_stream_state *stream; @@ -882,7 +880,7 @@ bool compute_mst_dsc_configs_for_state(struct drm_atomic_state *state, return false;
mutex_lock(&aconnector->mst_mgr.lock); - if (!compute_mst_dsc_configs_for_link(state, dc_state, stream->link)) { + if (!compute_mst_dsc_configs_for_link(state, dc_state, stream->link, vars)) { mutex_unlock(&aconnector->mst_mgr.lock); return false; } 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 b38bd68121ce..900d3f7a8498 100644 --- 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 @@ -39,8 +39,17 @@ void dm_dp_create_fake_mst_encoders(struct amdgpu_device *adev);
#if defined(CONFIG_DRM_AMD_DC_DCN) + +struct dsc_mst_fairness_vars { + int pbn; + bool dsc_enabled; + int bpp_x16; + struct amdgpu_dm_connector *aconnector; +}; + bool compute_mst_dsc_configs_for_state(struct drm_atomic_state *state, - struct dc_state *dc_state); + struct dc_state *dc_state, + struct dsc_mst_fairness_vars *vars); #endif
#endif