drm/msm/dp: Removed fixed nvid "support"

The "desc" member of struct dp_panel is zero-initialized during
allocation and never assigned, resulting in dp_ctrl_use_fixed_nvid()
never returning true. This returned boolean value is passed around but
never acted upon.

Perform constant propagation and remove the traces of "fixed nvid".
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Bjorn Andersson <quic_bjorande@quicinc.com>
Patchwork: https://patchwork.freedesktop.org/patch/585344/
Link: https://lore.kernel.org/r/20240328-msm-dp-cleanup-v2-2-a5aed9798d32@quicinc.comSigned-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

drivers/gpu/drm/msm/dp/dp_catalog.c

@@ -470,7 +470,7 @@ void dp_catalog_setup_peripheral_flush(struct dp_catalog *dp_catalog)
 
 void dp_catalog_ctrl_config_msa(struct dp_catalog *dp_catalog,
 					u32 rate, u32 stream_rate_khz,
-					bool fixed_nvid, bool is_ycbcr_420)
+					bool is_ycbcr_420)
 {
 	u32 pixel_m, pixel_n;
 	u32 mvid, nvid, pixel_div = 0, dispcc_input_rate;

drivers/gpu/drm/msm/dp/dp_catalog.h

@@ -100,7 +100,7 @@ void dp_catalog_ctrl_psr_mainlink_enable(struct dp_catalog *dp_catalog, bool ena
 void dp_catalog_setup_peripheral_flush(struct dp_catalog *dp_catalog);
 void dp_catalog_ctrl_config_misc(struct dp_catalog *dp_catalog, u32 cc, u32 tb);
 void dp_catalog_ctrl_config_msa(struct dp_catalog *dp_catalog, u32 rate,
-				u32 stream_rate_khz, bool fixed_nvid, bool is_ycbcr_420);
+				u32 stream_rate_khz, bool is_ycbcr_420);
 int dp_catalog_ctrl_set_pattern_state_bit(struct dp_catalog *dp_catalog, u32 pattern);
 u32 dp_catalog_hw_revision(const struct dp_catalog *dp_catalog);
 void dp_catalog_ctrl_reset(struct dp_catalog *dp_catalog);

drivers/gpu/drm/msm/dp/dp_ctrl.c

@@ -1566,21 +1566,6 @@ void dp_ctrl_phy_exit(struct dp_ctrl *dp_ctrl)
 			phy, phy->init_count, phy->power_count);
 }
 
-static bool dp_ctrl_use_fixed_nvid(struct dp_ctrl_private *ctrl)
-{
-	const u8 *dpcd = ctrl->panel->dpcd;
-
-	/*
-	 * For better interop experience, used a fixed NVID=0x8000
-	 * whenever connected to a VGA dongle downstream.
-	 */
-	if (drm_dp_is_branch(dpcd))
-		return (drm_dp_has_quirk(&ctrl->panel->desc,
-					 DP_DPCD_QUIRK_CONSTANT_N));
-
-	return false;
-}
-
 static int dp_ctrl_reinitialize_mainlink(struct dp_ctrl_private *ctrl)
 {
 	struct phy *phy = ctrl->phy;
@@ -2022,7 +2007,7 @@ int dp_ctrl_on_stream(struct dp_ctrl *dp_ctrl, bool force_link_train)
 
 	dp_catalog_ctrl_config_msa(ctrl->catalog,
 		ctrl->link->link_params.rate,
-		pixel_rate_orig, dp_ctrl_use_fixed_nvid(ctrl),
+		pixel_rate_orig,
 		ctrl->panel->dp_mode.out_fmt_is_yuv_420);
 
 	dp_ctrl_setup_tr_unit(ctrl);

drivers/gpu/drm/msm/dp/dp_panel.h

@@ -40,7 +40,6 @@ struct dp_panel {
 	u8 downstream_ports[DP_MAX_DOWNSTREAM_PORTS];
 
 	struct dp_link_info link_info;
-	struct drm_dp_desc desc;
 	struct edid *edid;
 	struct drm_connector *connector;
 	struct dp_display_mode dp_mode;