From: Kuogee Hsieh <khsieh@xxxxxxxxxxxxxx> [ Upstream commit 4b85d405cfe938ae7ad61656484ae88dee289e3b ] Reduce link rate and re start link training if link training 1 failed due to loss of clock recovery done to fix Link Layer CTS case 4.3.1.7. Also only update voltage and pre-emphasis swing level after link training started to fix Link Layer CTS case 4.3.1.6. Changes in V2: -- replaced cr_status with link_status[DP_LINK_STATUS_SIZE] -- replaced dp_ctrl_any_lane_cr_done() with dp_ctrl_colco_recovery_any_ok() -- replaced dp_ctrl_any_ane_cr_lose() with !drm_dp_clock_recovery_ok() Changes in V3: -- return failed if lane_count <= 1 Signed-off-by: Kuogee Hsieh <khsieh@xxxxxxxxxxxxxx> Reviewed-by: Stephen Boyd <swboyd@xxxxxxxxxxxx> Link: https://lore.kernel.org/r/1628196295-7382-3-git-send-email-khsieh@xxxxxxxxxxxxxx [remove unused cr_status variable] Signed-off-by: Rob Clark <robdclark@xxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/gpu/drm/msm/dp/dp_ctrl.c | 78 ++++++++++++++++++-------------- 1 file changed, 44 insertions(+), 34 deletions(-) diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c b/drivers/gpu/drm/msm/dp/dp_ctrl.c index 6856223e91e1..eb63920b36e8 100644 --- a/drivers/gpu/drm/msm/dp/dp_ctrl.c +++ b/drivers/gpu/drm/msm/dp/dp_ctrl.c @@ -83,13 +83,6 @@ struct dp_ctrl_private { struct completion video_comp; }; -struct dp_cr_status { - u8 lane_0_1; - u8 lane_2_3; -}; - -#define DP_LANE0_1_CR_DONE 0x11 - static int dp_aux_link_configure(struct drm_dp_aux *aux, struct dp_link_info *link) { @@ -1080,7 +1073,7 @@ static int dp_ctrl_read_link_status(struct dp_ctrl_private *ctrl, } static int dp_ctrl_link_train_1(struct dp_ctrl_private *ctrl, - struct dp_cr_status *cr, int *training_step) + int *training_step) { int tries, old_v_level, ret = 0; u8 link_status[DP_LINK_STATUS_SIZE]; @@ -1109,9 +1102,6 @@ static int dp_ctrl_link_train_1(struct dp_ctrl_private *ctrl, if (ret) return ret; - cr->lane_0_1 = link_status[0]; - cr->lane_2_3 = link_status[1]; - if (drm_dp_clock_recovery_ok(link_status, ctrl->link->link_params.num_lanes)) { return 0; @@ -1188,7 +1178,7 @@ static void dp_ctrl_clear_training_pattern(struct dp_ctrl_private *ctrl) } static int dp_ctrl_link_train_2(struct dp_ctrl_private *ctrl, - struct dp_cr_status *cr, int *training_step) + int *training_step) { int tries = 0, ret = 0; char pattern; @@ -1204,10 +1194,6 @@ static int dp_ctrl_link_train_2(struct dp_ctrl_private *ctrl, else pattern = DP_TRAINING_PATTERN_2; - ret = dp_ctrl_update_vx_px(ctrl); - if (ret) - return ret; - ret = dp_catalog_ctrl_set_pattern(ctrl->catalog, pattern); if (ret) return ret; @@ -1220,8 +1206,6 @@ static int dp_ctrl_link_train_2(struct dp_ctrl_private *ctrl, ret = dp_ctrl_read_link_status(ctrl, link_status); if (ret) return ret; - cr->lane_0_1 = link_status[0]; - cr->lane_2_3 = link_status[1]; if (drm_dp_channel_eq_ok(link_status, ctrl->link->link_params.num_lanes)) { @@ -1241,7 +1225,7 @@ static int dp_ctrl_link_train_2(struct dp_ctrl_private *ctrl, static int dp_ctrl_reinitialize_mainlink(struct dp_ctrl_private *ctrl); static int dp_ctrl_link_train(struct dp_ctrl_private *ctrl, - struct dp_cr_status *cr, int *training_step) + int *training_step) { int ret = 0; u8 encoding = DP_SET_ANSI_8B10B; @@ -1257,7 +1241,7 @@ static int dp_ctrl_link_train(struct dp_ctrl_private *ctrl, drm_dp_dpcd_write(ctrl->aux, DP_MAIN_LINK_CHANNEL_CODING_SET, &encoding, 1); - ret = dp_ctrl_link_train_1(ctrl, cr, training_step); + ret = dp_ctrl_link_train_1(ctrl, training_step); if (ret) { DRM_ERROR("link training #1 failed. ret=%d\n", ret); goto end; @@ -1266,7 +1250,7 @@ static int dp_ctrl_link_train(struct dp_ctrl_private *ctrl, /* print success info as this is a result of user initiated action */ DRM_DEBUG_DP("link training #1 successful\n"); - ret = dp_ctrl_link_train_2(ctrl, cr, training_step); + ret = dp_ctrl_link_train_2(ctrl, training_step); if (ret) { DRM_ERROR("link training #2 failed. ret=%d\n", ret); goto end; @@ -1282,7 +1266,7 @@ static int dp_ctrl_link_train(struct dp_ctrl_private *ctrl, } static int dp_ctrl_setup_main_link(struct dp_ctrl_private *ctrl, - struct dp_cr_status *cr, int *training_step) + int *training_step) { int ret = 0; @@ -1297,7 +1281,7 @@ static int dp_ctrl_setup_main_link(struct dp_ctrl_private *ctrl, * a link training pattern, we have to first do soft reset. */ - ret = dp_ctrl_link_train(ctrl, cr, training_step); + ret = dp_ctrl_link_train(ctrl, training_step); return ret; } @@ -1494,14 +1478,13 @@ static int dp_ctrl_deinitialize_mainlink(struct dp_ctrl_private *ctrl) static int dp_ctrl_link_maintenance(struct dp_ctrl_private *ctrl) { int ret = 0; - struct dp_cr_status cr; int training_step = DP_TRAINING_NONE; dp_ctrl_push_idle(&ctrl->dp_ctrl); ctrl->dp_ctrl.pixel_rate = ctrl->panel->dp_mode.drm_mode.clock; - ret = dp_ctrl_setup_main_link(ctrl, &cr, &training_step); + ret = dp_ctrl_setup_main_link(ctrl, &training_step); if (ret) goto end; @@ -1632,6 +1615,25 @@ void dp_ctrl_handle_sink_request(struct dp_ctrl *dp_ctrl) } } +static bool dp_ctrl_clock_recovery_any_ok( + const u8 link_status[DP_LINK_STATUS_SIZE], + int lane_count) +{ + int reduced_cnt; + + if (lane_count <= 1) + return false; + + /* + * only interested in the lane number after reduced + * lane_count = 4, then only interested in 2 lanes + * lane_count = 2, then only interested in 1 lane + */ + reduced_cnt = lane_count >> 1; + + return drm_dp_clock_recovery_ok(link_status, reduced_cnt); +} + int dp_ctrl_on_link(struct dp_ctrl *dp_ctrl) { int rc = 0; @@ -1639,7 +1641,7 @@ int dp_ctrl_on_link(struct dp_ctrl *dp_ctrl) u32 rate = 0; int link_train_max_retries = 5; u32 const phy_cts_pixel_clk_khz = 148500; - struct dp_cr_status cr; + u8 link_status[DP_LINK_STATUS_SIZE]; unsigned int training_step; if (!dp_ctrl) @@ -1679,19 +1681,21 @@ int dp_ctrl_on_link(struct dp_ctrl *dp_ctrl) } training_step = DP_TRAINING_NONE; - rc = dp_ctrl_setup_main_link(ctrl, &cr, &training_step); + rc = dp_ctrl_setup_main_link(ctrl, &training_step); if (rc == 0) { /* training completed successfully */ break; } else if (training_step == DP_TRAINING_1) { /* link train_1 failed */ - if (!dp_catalog_link_is_connected(ctrl->catalog)) { + if (!dp_catalog_link_is_connected(ctrl->catalog)) break; - } + + dp_ctrl_read_link_status(ctrl, link_status); rc = dp_ctrl_link_rate_down_shift(ctrl); if (rc < 0) { /* already in RBR = 1.6G */ - if (cr.lane_0_1 & DP_LANE0_1_CR_DONE) { + if (dp_ctrl_clock_recovery_any_ok(link_status, + ctrl->link->link_params.num_lanes)) { /* * some lanes are ready, * reduce lane number @@ -1707,12 +1711,18 @@ int dp_ctrl_on_link(struct dp_ctrl *dp_ctrl) } } } else if (training_step == DP_TRAINING_2) { - /* link train_2 failed, lower lane rate */ - if (!dp_catalog_link_is_connected(ctrl->catalog)) { + /* link train_2 failed */ + if (!dp_catalog_link_is_connected(ctrl->catalog)) break; - } - rc = dp_ctrl_link_lane_down_shift(ctrl); + dp_ctrl_read_link_status(ctrl, link_status); + + if (!drm_dp_clock_recovery_ok(link_status, + ctrl->link->link_params.num_lanes)) + rc = dp_ctrl_link_rate_down_shift(ctrl); + else + rc = dp_ctrl_link_lane_down_shift(ctrl); + if (rc < 0) { /* end with failure */ break; /* lane == 1 already */ -- 2.30.2
