video: tegra20: dsi: calculate packet parameters for video mode

Calculate packet parameters for video mode same way it is done or
command mode, by halving timings plugged into equations.

Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
diff --git a/drivers/video/tegra20/tegra-dsi.c b/drivers/video/tegra20/tegra-dsi.c
index e1502d8..2beb9ec 100644
--- a/drivers/video/tegra20/tegra-dsi.c
+++ b/drivers/video/tegra20/tegra-dsi.c
@@ -697,12 +697,19 @@
 		/* horizontal back porch */
 		hbp = timing->hback_porch.typ * mul / div;
 
-		if ((mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE) == 0)
-			hbp += hsw;
-
 		/* horizontal front porch */
 		hfp = timing->hfront_porch.typ * mul / div;
 
+		if (priv->master || priv->slave) {
+			hact /= 2;
+			hsw /= 2;
+			hbp = hbp / 2 - 1;
+			hfp /= 2;
+		}
+
+		if ((mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE) == 0)
+			hbp += hsw;
+
 		/* subtract packet overhead */
 		hsw -= 10;
 		hbp -= 14;