From: Maxime Ripard <maxime.ripard@free-electrons.com>
Date: Sat, 27 May 2017 18:09:29 +0200
Subject: drm/sun4i: tcon: Fix tcon channel 1 backporch calculation
Git-commit: 3cb2f46b3da4c45342414c63cd465de483cb102a
Patch-mainline: v4.13-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

It seems like what's called a backporch in the datasheet is actually the
backporch plus the sync period. Fix that in our driver.

Acked-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/sun4i/sun4i_tcon.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/gpu/drm/sun4i/sun4i_tcon.c
+++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c
@@ -269,7 +269,7 @@ void sun4i_tcon1_mode_set(struct sun4i_t
 		     SUN4I_TCON1_BASIC2_Y(mode->crtc_vdisplay));
 
 	/* Set horizontal display timings */
-	bp = mode->crtc_htotal - mode->crtc_hsync_end;
+	bp = mode->crtc_htotal - mode->crtc_hsync_start;
 	DRM_DEBUG_DRIVER("Setting horizontal total %d, backporch %d\n",
 			 mode->htotal, bp);
 	regmap_write(tcon->regs, SUN4I_TCON1_BASIC3_REG,
@@ -277,7 +277,7 @@ void sun4i_tcon1_mode_set(struct sun4i_t
 		     SUN4I_TCON1_BASIC3_H_BACKPORCH(bp));
 
 	/* Set vertical display timings */
-	bp = mode->crtc_vtotal - mode->crtc_vsync_end;
+	bp = mode->crtc_vtotal - mode->crtc_vsync_start;
 	DRM_DEBUG_DRIVER("Setting vertical total %d, backporch %d\n",
 			 mode->vtotal, bp);
 	regmap_write(tcon->regs, SUN4I_TCON1_BASIC4_REG,