msm: mdss: Tune the mdss event timer wakeup time

Adjust the mdss event timer to wakeup before the readpointer
to help with latency issues.

Crs-Fixed: 840497
Change-Id: I384d7e13af1e4893aa200240c6a057ebc2bf92c6
Signed-off-by: Siddhartha Agrawal <agrawals@codeaurora.org>

Documentation/devicetree/bindings/fb/mdss-dsi-panel.txt

@@ -450,6 +450,8 @@ Optional properites:
 					slice.
 - qcom,mdss-dsc-config-by-manufacture-cmd: A boolean to indicates panel use manufacture command to setup pps
 					instead of standard dcs type 0x0A.
+- qcom,adjust-timer-wakeup-ms:		An integer value to indicate the timer delay(in ms) to accommodate
+					s/w delay while configuring the event timer wakeup logic.
 
 Note, if a given optional qcom,* binding is not present, then the driver will configure
 the default values specified.
@@ -591,6 +593,7 @@ Example:
 		qcom,mdss-dsi-panel-orientation = "180"
 		qcom,mdss-dsi-force-clock-lane-hs;
 		qcom,compression-mode = "dsc";
+		qcom,adjust-timer-wakeup-ms = <1>;
 		qcom,panel-supply-entries {
 			#address-cells = <1>;
 			#size-cells = <0>;

drivers/video/fbdev/msm/mdss_dsi_panel.c

@@ -2310,6 +2310,9 @@ static int mdss_panel_parse_dt(struct device_node *np,
 	mdss_dsi_parse_dcs_cmds(np, &ctrl_pdata->off_cmds,
 		"qcom,mdss-dsi-off-command", "qcom,mdss-dsi-off-command-state");
 
+	rc = of_property_read_u32(np, "qcom,adjust-timer-wakeup-ms", &tmp);
+	pinfo->adjust_timer_delay_ms = (!rc ? tmp : 0);
+
 	pinfo->mipi.force_clk_lane_hs = of_property_read_bool(np,
 		"qcom,mdss-dsi-force-clock-lane-hs");
 

drivers/video/fbdev/msm/mdss_mdp_ctl.c

@@ -4096,7 +4096,8 @@ int mdss_mdp_display_wakeup_time(struct mdss_mdp_ctl *ctl,
 	struct mdss_panel_info *pinfo;
 	u32 clk_rate, clk_period;
 	u32 current_line, total_line;
-	u32 time_of_line, time_to_vsync;
+	u32 time_of_line, time_to_vsync, adjust_line_ns;
+
 	ktime_t current_time = ktime_get();
 
 	if (!ctl->ops.read_line_cnt_fnc)
@@ -4141,6 +4142,16 @@ int mdss_mdp_display_wakeup_time(struct mdss_mdp_ctl *ctl,
 		return -EINVAL;
 
 	time_to_vsync = time_of_line * (total_line - current_line);
+
+	if (pinfo->adjust_timer_delay_ms) {
+		adjust_line_ns = pinfo->adjust_timer_delay_ms
+			* 1000000; /* convert to ns */
+
+		/* Ignore large values of adjust_line_ns\ */
+		if (time_to_vsync > adjust_line_ns)
+			time_to_vsync -= adjust_line_ns;
+	}
+
 	if (!time_to_vsync)
 		return -EINVAL;
 

drivers/video/fbdev/msm/mdss_panel.c

@@ -365,6 +365,8 @@ static int _create_dsi_panel_nodes(struct mdss_panel_debugfs_info *dfs,
 			(char *)&pinfo->mipi.rx_eot_ignore);
 	debugfs_create_u8("tx_eot_append", 0644, mipi_root,
 			(char *)&pinfo->mipi.tx_eot_append);
+	debugfs_create_u32("adjust_timer_ms", 0644, mipi_root,
+			(u32 *)&pinfo->adjust_timer_delay_ms);
 
 	/* TE reltaed nodes */
 	debugfs_create_u32("te_tear_check_en", 0644, te_root,
@@ -539,6 +541,8 @@ void mdss_panel_debugfsinfo_to_panelinfo(struct mdss_panel_info *panel_info)
 		pinfo->bl_min = dfs_info->panel_info.bl_min;
 		pinfo->bl_max = dfs_info->panel_info.bl_max;
 		pinfo->brightness_max = dfs_info->panel_info.brightness_max;
+		pinfo->adjust_timer_delay_ms =
+			dfs_info->panel_info.adjust_timer_delay_ms;
 
 		if ((pinfo->type == MIPI_CMD_PANEL) ||
 		    (pinfo->type == MIPI_VIDEO_PANEL)) {

drivers/video/fbdev/msm/mdss_panel.h

@@ -575,6 +575,12 @@ struct mdss_panel_info {
 	struct lvds_panel_info lvds;
 	struct edp_panel_info edp;
 
+	/*
+	 * Delay(in ms) to accommodate s/w delay while
+	 * configuring the event timer wakeup logic.
+	 */
+	u32 adjust_timer_delay_ms;
+
 	/* debugfs structure for the panel */
 	struct mdss_panel_debugfs_info *debugfs_info;
 };