disp: msm: sde: adjust qsync linecount calculation

Adjust the QSYNC line count calculation to compensate for the
idle time, when no transfers are actively taking place.

Change-Id: If91eab25321eea6e6880f07605c5a9c1b7b7ee05
Signed-off-by: Steve Cohen <cohens@codeaurora.org>

msm/sde/sde_encoder.c

@@ -4043,6 +4043,24 @@ void sde_encoder_helper_get_pp_line_count(struct drm_encoder *drm_enc,
 	}
 }
 
+void sde_encoder_helper_get_transfer_time(struct drm_encoder *drm_enc,
+			u32 *transfer_time_us)
+{
+	struct sde_encoder_virt *sde_enc;
+	struct msm_mode_info *info;
+
+	if (!drm_enc || !transfer_time_us) {
+		SDE_ERROR("bad arg: encoder:%d transfer_time:%d\n", !drm_enc,
+				!transfer_time_us);
+		return;
+	}
+
+	sde_enc = to_sde_encoder_virt(drm_enc);
+	info = &sde_enc->mode_info;
+
+	*transfer_time_us = info->mdp_transfer_time_us;
+}
+
 int sde_encoder_helper_reset_mixers(struct sde_encoder_phys *phys_enc,
 		struct drm_framebuffer *fb)
 {

msm/sde/sde_encoder_phys.h

@@ -539,6 +539,14 @@ void sde_encoder_phys_setup_cdm(struct sde_encoder_phys *phys_enc,
 void sde_encoder_helper_get_pp_line_count(struct drm_encoder *drm_enc,
 		struct sde_hw_pp_vsync_info *info);
 
+/**
+ * sde_encoder_helper_get_transfer_time - get the mdp transfer time in usecs
+ * @drm_enc: Pointer to drm encoder structure
+ * @transfer_time_us: Pointer to store the output value
+ */
+void sde_encoder_helper_get_transfer_time(struct drm_encoder *drm_enc,
+		u32 *transfer_time_us);
+
 /**
  * sde_encoder_helper_trigger_flush - control flush helper function
  *	This helper function may be optionally specified by physical

msm/sde/sde_encoder_phys_cmd.c

@@ -932,7 +932,7 @@ static int _get_tearcheck_threshold(struct sde_encoder_phys *phys_enc,
 	struct drm_connector *conn = phys_enc->connector;
 	u32 qsync_mode;
 	struct drm_display_mode *mode;
-	u32 threshold_lines = 0;
+	u32 threshold_lines = DEFAULT_TEARCHECK_SYNC_THRESH_START;
 	struct sde_encoder_phys_cmd *cmd_enc =
 			to_sde_encoder_phys_cmd(phys_enc);
 
@@ -950,8 +950,9 @@ static int _get_tearcheck_threshold(struct sde_encoder_phys *phys_enc,
 		u32 slow_time_ns;
 		u32 default_time_ns;
 		u32 extra_time_ns;
-		u32 total_extra_lines;
 		u32 default_line_time_ns;
+		u32 idle_time_ns = 0;
+		u32 transfer_time_us = 0;
 
 		if (phys_enc->parent_ops.get_qsync_fps)
 			phys_enc->parent_ops.get_qsync_fps(
@@ -974,27 +975,31 @@ static int _get_tearcheck_threshold(struct sde_encoder_phys *phys_enc,
 		/* Calculate the number of extra lines*/
 		slow_time_ns = (1 * 1000000000) / qsync_min_fps;
 		default_time_ns = (1 * 1000000000) / default_fps;
-		extra_time_ns = slow_time_ns - default_time_ns;
+		sde_encoder_helper_get_transfer_time(phys_enc->parent,
+				&transfer_time_us);
+		if (transfer_time_us)
+			idle_time_ns = default_time_ns -
+					(1000 * transfer_time_us);
+
+		extra_time_ns = slow_time_ns - default_time_ns + idle_time_ns;
 		default_line_time_ns = (1 * 1000000000) / (default_fps * yres);
 
-		total_extra_lines = extra_time_ns / default_line_time_ns;
+		threshold_lines = extra_time_ns / default_line_time_ns;
-		threshold_lines += total_extra_lines;
 
 		SDE_DEBUG_CMDENC(cmd_enc, "slow:%d default:%d extra:%d(ns)\n",
 			slow_time_ns, default_time_ns, extra_time_ns);
-		SDE_DEBUG_CMDENC(cmd_enc, "extra_lines:%d threshold:%d\n",
+		SDE_DEBUG_CMDENC(cmd_enc, "xfer:%d(us) idle:%d(ns) lines:%d\n",
-			total_extra_lines, threshold_lines);
+			transfer_time_us, idle_time_ns, threshold_lines);
 		SDE_DEBUG_CMDENC(cmd_enc, "min_fps:%d fps:%d yres:%d\n",
 			qsync_min_fps, default_fps, yres);
 
 		SDE_EVT32(qsync_mode, qsync_min_fps, extra_time_ns, default_fps,
-			yres, threshold_lines);
+			yres, transfer_time_us, threshold_lines);
 
 		*extra_frame_trigger_time = extra_time_ns;
 	}
 
 exit:
-	threshold_lines += DEFAULT_TEARCHECK_SYNC_THRESH_START;
 
 	return threshold_lines;
 }