6.6-stable review patch. If anyone has any objections, please let me know.
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From: Dmitry Baryshkov dmitry.baryshkov@linaro.org
[ Upstream commit 22578178e5dd6d3aa4490879df8b6c2977d980be ]
Both dp_link_adjust_levels() and dp_ctrl_update_vx_px() limit swing and pre-emphasis to 2, while the real maximum value for the sum of the voltage swing and pre-emphasis is 3. Fix the DP code to remove this limitation.
Fixes: c943b4948b58 ("drm/msm/dp: add displayPort driver support") Signed-off-by: Dmitry Baryshkov dmitry.baryshkov@linaro.org Reviewed-by: Kuogee Hsieh quic_khsieh@quicinc.com Tested-by: Kuogee Hsieh quic_khsieh@quicinc.com Patchwork: https://patchwork.freedesktop.org/patch/577006/ Link: https://lore.kernel.org/r/20240203-dp-swing-3-v1-1-6545e1706196@linaro.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/msm/dp/dp_ctrl.c | 6 +++--- drivers/gpu/drm/msm/dp/dp_link.c | 22 +++++++++++----------- drivers/gpu/drm/msm/dp/dp_link.h | 14 +------------- 3 files changed, 15 insertions(+), 27 deletions(-)
diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c b/drivers/gpu/drm/msm/dp/dp_ctrl.c index fb588fde298a2..780e9747be1fb 100644 --- a/drivers/gpu/drm/msm/dp/dp_ctrl.c +++ b/drivers/gpu/drm/msm/dp/dp_ctrl.c @@ -1019,14 +1019,14 @@ static int dp_ctrl_update_vx_px(struct dp_ctrl_private *ctrl) if (ret) return ret;
- if (voltage_swing_level >= DP_TRAIN_VOLTAGE_SWING_MAX) { + if (voltage_swing_level >= DP_TRAIN_LEVEL_MAX) { drm_dbg_dp(ctrl->drm_dev, "max. voltage swing level reached %d\n", voltage_swing_level); max_level_reached |= DP_TRAIN_MAX_SWING_REACHED; }
- if (pre_emphasis_level >= DP_TRAIN_PRE_EMPHASIS_MAX) { + if (pre_emphasis_level >= DP_TRAIN_LEVEL_MAX) { drm_dbg_dp(ctrl->drm_dev, "max. pre-emphasis level reached %d\n", pre_emphasis_level); @@ -1117,7 +1117,7 @@ static int dp_ctrl_link_train_1(struct dp_ctrl_private *ctrl, }
if (ctrl->link->phy_params.v_level >= - DP_TRAIN_VOLTAGE_SWING_MAX) { + DP_TRAIN_LEVEL_MAX) { DRM_ERROR_RATELIMITED("max v_level reached\n"); return -EAGAIN; } diff --git a/drivers/gpu/drm/msm/dp/dp_link.c b/drivers/gpu/drm/msm/dp/dp_link.c index 25950171caf3e..a198af7b2d449 100644 --- a/drivers/gpu/drm/msm/dp/dp_link.c +++ b/drivers/gpu/drm/msm/dp/dp_link.c @@ -1141,6 +1141,7 @@ int dp_link_get_colorimetry_config(struct dp_link *dp_link) int dp_link_adjust_levels(struct dp_link *dp_link, u8 *link_status) { int i; + u8 max_p_level; int v_max = 0, p_max = 0; struct dp_link_private *link;
@@ -1172,30 +1173,29 @@ int dp_link_adjust_levels(struct dp_link *dp_link, u8 *link_status) * Adjust the voltage swing and pre-emphasis level combination to within * the allowable range. */ - if (dp_link->phy_params.v_level > DP_TRAIN_VOLTAGE_SWING_MAX) { + if (dp_link->phy_params.v_level > DP_TRAIN_LEVEL_MAX) { drm_dbg_dp(link->drm_dev, "Requested vSwingLevel=%d, change to %d\n", dp_link->phy_params.v_level, - DP_TRAIN_VOLTAGE_SWING_MAX); - dp_link->phy_params.v_level = DP_TRAIN_VOLTAGE_SWING_MAX; + DP_TRAIN_LEVEL_MAX); + dp_link->phy_params.v_level = DP_TRAIN_LEVEL_MAX; }
- if (dp_link->phy_params.p_level > DP_TRAIN_PRE_EMPHASIS_MAX) { + if (dp_link->phy_params.p_level > DP_TRAIN_LEVEL_MAX) { drm_dbg_dp(link->drm_dev, "Requested preEmphasisLevel=%d, change to %d\n", dp_link->phy_params.p_level, - DP_TRAIN_PRE_EMPHASIS_MAX); - dp_link->phy_params.p_level = DP_TRAIN_PRE_EMPHASIS_MAX; + DP_TRAIN_LEVEL_MAX); + dp_link->phy_params.p_level = DP_TRAIN_LEVEL_MAX; }
- if ((dp_link->phy_params.p_level > DP_TRAIN_PRE_EMPHASIS_LVL_1) - && (dp_link->phy_params.v_level == - DP_TRAIN_VOLTAGE_SWING_LVL_2)) { + max_p_level = DP_TRAIN_LEVEL_MAX - dp_link->phy_params.v_level; + if (dp_link->phy_params.p_level > max_p_level) { drm_dbg_dp(link->drm_dev, "Requested preEmphasisLevel=%d, change to %d\n", dp_link->phy_params.p_level, - DP_TRAIN_PRE_EMPHASIS_LVL_1); - dp_link->phy_params.p_level = DP_TRAIN_PRE_EMPHASIS_LVL_1; + max_p_level); + dp_link->phy_params.p_level = max_p_level; }
drm_dbg_dp(link->drm_dev, "adjusted: v_level=%d, p_level=%d\n", diff --git a/drivers/gpu/drm/msm/dp/dp_link.h b/drivers/gpu/drm/msm/dp/dp_link.h index 9dd4dd9265304..79c3a02b8dacd 100644 --- a/drivers/gpu/drm/msm/dp/dp_link.h +++ b/drivers/gpu/drm/msm/dp/dp_link.h @@ -19,19 +19,7 @@ struct dp_link_info { unsigned long capabilities; };
-enum dp_link_voltage_level { - DP_TRAIN_VOLTAGE_SWING_LVL_0 = 0, - DP_TRAIN_VOLTAGE_SWING_LVL_1 = 1, - DP_TRAIN_VOLTAGE_SWING_LVL_2 = 2, - DP_TRAIN_VOLTAGE_SWING_MAX = DP_TRAIN_VOLTAGE_SWING_LVL_2, -}; - -enum dp_link_preemaphasis_level { - DP_TRAIN_PRE_EMPHASIS_LVL_0 = 0, - DP_TRAIN_PRE_EMPHASIS_LVL_1 = 1, - DP_TRAIN_PRE_EMPHASIS_LVL_2 = 2, - DP_TRAIN_PRE_EMPHASIS_MAX = DP_TRAIN_PRE_EMPHASIS_LVL_2, -}; +#define DP_TRAIN_LEVEL_MAX 3
struct dp_link_test_video { u32 test_video_pattern;