Re: [PATCH v2 1/2] drm/msm/dp: Add support for SC7280 eDP

Quoting Sankeerth Billakanti (2021-10-20 05:14:10)

diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c b/drivers/gpu/drm/msm/dp/dp_ctrl.c index 62e75dc..9fea49c 100644 --- a/drivers/gpu/drm/msm/dp/dp_ctrl.c +++ b/drivers/gpu/drm/msm/dp/dp_ctrl.c @@ -1238,9 +1240,21 @@ static int dp_ctrl_link_train(struct dp_ctrl_private *ctrl, link_info.capabilities = DP_LINK_CAP_ENHANCED_FRAMING;

    dp_aux_link_configure(ctrl->aux, &link_info);

•   if (dpcd[DP_MAX_DOWNSPREAD] & DP_MAX_DOWNSPREAD_0_5) {
  

Please add a static inline macro in include/drm/drm_dp_helper.h that makes this more readable. Something similar to drm_dp_is_branch() but with a human readable replacement for "is_branch". Maybe drm_dp_ssc()?

•           ssc = DP_SPREAD_AMP_0_5;
  

•           drm_dp_dpcd_write(ctrl->aux, DP_DOWNSPREAD_CTRL, &ssc, 1);
  

•   }
  

•   drm_dp_dpcd_write(ctrl->aux, DP_MAIN_LINK_CHANNEL_CODING_SET,
                            &encoding, 1);
  
  

•   if (dpcd[DP_EDP_CONFIGURATION_CAP] & DP_ALTERNATE_SCRAMBLER_RESET_CAP) {
  

And this one already has a helper, drm_dp_alternate_scrambler_reset_cap().

•           assr = DP_ALTERNATE_SCRAMBLER_RESET_ENABLE;
  

•           drm_dp_dpcd_write(ctrl->aux, DP_EDP_CONFIGURATION_SET,
  

•                           &assr, 1);
  

•   }
  

•   ret = dp_ctrl_link_train_1(ctrl, training_step);
    if (ret) {
            DRM_ERROR("link training #1 failed. ret=%d\n", ret);
  

@@ -1312,9 +1326,11 @@ static int dp_ctrl_enable_mainlink_clocks(struct dp_ctrl_private *ctrl) struct dp_io *dp_io = &ctrl->parser->io; struct phy *phy = dp_io->phy; struct phy_configure_opts_dp *opts_dp = &dp_io->phy_opts.dp;

•   const u8 *dpcd = ctrl->panel->dpcd;
  
    opts_dp->lanes = ctrl->link->link_params.num_lanes;
    opts_dp->link_rate = ctrl->link->link_params.rate / 100;
  

•   opts_dp->ssc = dpcd[DP_MAX_DOWNSPREAD] & DP_MAX_DOWNSPREAD_0_5;
    dp_ctrl_set_clock_rate(ctrl, DP_CTRL_PM, "ctrl_link",
                                    ctrl->link->link_params.rate * 1000);
  
  

@@ -1406,7 +1422,7 @@ void dp_ctrl_host_deinit(struct dp_ctrl *dp_ctrl)

static bool dp_ctrl_use_fixed_nvid(struct dp_ctrl_private *ctrl) {

•   u8 *dpcd = ctrl->panel->dpcd;
  

•   const u8 *dpcd = ctrl->panel->dpcd;
  
    /*
     * For better interop experience, used a fixed NVID=0x8000
  

diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c index c867745..c16311b 100644 --- a/drivers/gpu/drm/msm/dp/dp_display.c +++ b/drivers/gpu/drm/msm/dp/dp_display.c @@ -144,8 +144,16 @@ static const struct msm_dp_config sc8180x_dp_cfg = { .num_descs = 3, };

+static const struct msm_dp_config sc7280_dp_cfg = {

•   .descs = (struct msm_dp_desc[]) {
  

const

•           { .io_start = 0x0aea0000, .connector_type = DRM_MODE_CONNECTOR_eDP },
  

•   },
  

•   .num_descs = 1,
  

+};

static const struct of_device_id dp_dt_match[] = { { .compatible = "qcom,sc7180-dp", .data = &sc7180_dp_cfg },

•   { .compatible = "qcom,sc7280-edp", .data = &sc7280_dp_cfg },
    { .compatible = "qcom,sc8180x-dp", .data = &sc8180x_dp_cfg },
    { .compatible = "qcom,sc8180x-edp", .data = &sc8180x_dp_cfg },
    {}
  

@@ -1440,7 +1448,7 @@ void msm_dp_irq_postinstall(struct msm_dp *dp_display)

    dp_hpd_event_setup(dp);

•   dp_add_event(dp, EV_HPD_INIT_SETUP, 0, 100);
  

•   dp_add_event(dp, EV_HPD_INIT_SETUP, 0, 1);
  

This has no explanation. What is it?