msm: mdss: trigger BTA during active region of display

If DSI SW requests BTA very close to end of blanking or
start of active region and the BTA acknowledgment takes
more then one BLLP time to complete, then it will have side
effects on video timing generator since DSI will not be
receiving pixel data until BTA finishes. So always wait for
video done interrupt and skip blanking to ensure we fall into
active region before sending BTA request. This will
ensure BTA request is always sent during active region.

Change-Id: Ia9e1193f0229df8c552c3ba0287a5a60837ae540
Signed-off-by: Sandeep Panda <spanda@codeaurora.org>

1 files changed, 37 insertions, 31 deletions

diff --git a/drivers/video/fbdev/msm/mdss_dsi_host.c b/drivers/video/fbdev/msm/mdss_dsi_host.c
index 04ce8d6c11d2..734d3bee8fd0 100644
--- a/drivers/video/fbdev/msm/mdss_dsi_host.c
+++ b/drivers/video/fbdev/msm/mdss_dsi_host.c
@@ -1425,6 +1425,35 @@ void mdss_dsi_ctrl_setup(struct mdss_dsi_ctrl_pdata *ctrl)
 	mdss_dsi_op_mode_config(pdata->panel_info.mipi.mode, pdata);
 }
 
+static int mdss_dsi_wait4video_eng_busy(struct mdss_dsi_ctrl_pdata *ctrl)
+{
+	int ret = 0;
+	u32 v_total = 0, v_blank = 0, sleep_ms = 0, fps = 0;
+	struct mdss_panel_info *pinfo = &ctrl->panel_data.panel_info;
+
+	if (ctrl->panel_mode == DSI_CMD_MODE)
+		return ret;
+
+	if (ctrl->ctrl_state & CTRL_STATE_MDP_ACTIVE) {
+		mdss_dsi_wait4video_done(ctrl);
+		v_total = mdss_panel_get_vtotal(pinfo);
+		v_blank = pinfo->lcdc.v_back_porch + pinfo->lcdc.v_front_porch +
+			pinfo->lcdc.v_pulse_width;
+		if (pinfo->dynamic_fps && pinfo->current_fps)
+			fps = pinfo->current_fps;
+		else
+			fps = pinfo->mipi.frame_rate;
+
+		sleep_ms = CEIL((v_blank * 1000), (v_total * fps)) + 1;
+		/* delay sleep_ms to skip BLLP */
+		if (sleep_ms)
+			udelay(sleep_ms * 1000);
+		ret = 1;
+	}
+
+	return ret;
+}
+
 /**
  * mdss_dsi_bta_status_check() - Check dsi panel status through bta check
  * @ctrl_pdata: pointer to the dsi controller structure
@@ -1465,6 +1494,7 @@ int mdss_dsi_bta_status_check(struct mdss_dsi_ctrl_pdata *ctrl_pdata)
 	reinit_completion(&ctrl_pdata->bta_comp);
 	mdss_dsi_enable_irq(ctrl_pdata, DSI_BTA_TERM);
 	spin_unlock_irqrestore(&ctrl_pdata->mdp_lock, flag);
+	mdss_dsi_wait4video_eng_busy(ctrl_pdata);
 	/* mask out overflow errors */
 	if (ignore_underflow)
 		mdss_dsi_set_reg(ctrl_pdata, 0x10c, 0x0f0000, 0x0f0000);
@@ -2350,15 +2380,20 @@ void mdss_dsi_wait4video_done(struct mdss_dsi_ctrl_pdata *ctrl)
 	/* DSI_INTL_CTRL */
 	data = MIPI_INP((ctrl->ctrl_base) + 0x0110);
 	data &= DSI_INTR_TOTAL_MASK;
-	data |= DSI_INTR_VIDEO_DONE_MASK;
 
-	MIPI_OUTP((ctrl->ctrl_base) + 0x0110, data);
+	/* clear previous VIDEO_DONE interrupt */
+	MIPI_OUTP((ctrl->ctrl_base) + 0x0110, (data | DSI_INTR_VIDEO_DONE));
+	wmb(); /* ensure interrupt is cleared */
 
 	spin_lock_irqsave(&ctrl->mdp_lock, flag);
 	reinit_completion(&ctrl->video_comp);
 	mdss_dsi_enable_irq(ctrl, DSI_VIDEO_TERM);
 	spin_unlock_irqrestore(&ctrl->mdp_lock, flag);
 
+	data |= DSI_INTR_VIDEO_DONE_MASK;
+	MIPI_OUTP((ctrl->ctrl_base) + 0x0110, data);
+	wmb(); /* ensure interrupt is enabled */
+
 	wait_for_completion_timeout(&ctrl->video_comp,
 			msecs_to_jiffies(VSYNC_PERIOD * 4));
 
@@ -2368,35 +2403,6 @@ void mdss_dsi_wait4video_done(struct mdss_dsi_ctrl_pdata *ctrl)
 	MIPI_OUTP((ctrl->ctrl_base) + 0x0110, data);
 }
 
-static int mdss_dsi_wait4video_eng_busy(struct mdss_dsi_ctrl_pdata *ctrl)
-{
-	int ret = 0;
-	u32 v_total = 0, v_blank = 0, sleep_ms = 0, fps = 0;
-	struct mdss_panel_info *pinfo = &ctrl->panel_data.panel_info;
-
-	if (ctrl->panel_mode == DSI_CMD_MODE)
-		return ret;
-
-	if (ctrl->ctrl_state & CTRL_STATE_MDP_ACTIVE) {
-		mdss_dsi_wait4video_done(ctrl);
-		v_total = mdss_panel_get_vtotal(pinfo);
-		v_blank = pinfo->lcdc.v_back_porch + pinfo->lcdc.v_front_porch +
-			pinfo->lcdc.v_pulse_width;
-		if (pinfo->dynamic_fps && pinfo->current_fps)
-			fps = pinfo->current_fps;
-		else
-			fps = pinfo->mipi.frame_rate;
-
-		sleep_ms = CEIL((v_blank * 1000), (v_total * fps)) + 1;
-		/* delay sleep_ms to skip BLLP */
-		if (sleep_ms)
-			udelay(sleep_ms * 1000);
-		ret = 1;
-	}
-
-	return ret;
-}
-
 void mdss_dsi_cmd_mdp_start(struct mdss_dsi_ctrl_pdata *ctrl)
 {
 	unsigned long flag;