[PATCH 2/2] drm: rcar-du: lvds: fix LVDS startup on R-Car gen2

[Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>]

[-- Attachment #1: drm-rcar-du-lvds-fix-LVDS-startup-on-R-Car-gen2.patch --]
[-- Type: text/plain, Size: 1567 bytes --]

According to the latest revision 2.00 of the R-Car gen2 manual, the LVDS
must be enabled and the bias crcuit  enabled after the LVDS I/O pins are
enabled, not before --  fix the gen2 LVDS startup sequence accordingly.

Fixes: 90374b5c25c9 ("drm/rcar-du: Add internal LVDS encoder support")
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>

---
 drivers/gpu/drm/rcar-du/rcar_du_lvdsenc.c |   11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

Index: linux/drivers/gpu/drm/rcar-du/rcar_du_lvdsenc.c
===================================================================
--- linux.orig/drivers/gpu/drm/rcar-du/rcar_du_lvdsenc.c
+++ linux/drivers/gpu/drm/rcar-du/rcar_du_lvdsenc.c
@@ -59,11 +59,8 @@ static void rcar_du_lvdsenc_start_gen2(s
 
 	rcar_lvds_write(lvds, LVDPLLCR, pllcr);
 
-	/*
-	 * Set the  LVDS mode, select the input, enable LVDS operation,
-	 * and turn bias circuitry on.
-	 */
-	lvdcr0 = (lvds->mode << LVDCR0_LVMD_SHIFT) | LVDCR0_BEN | LVDCR0_LVEN;
+	/* Select the input and set the LVDS mode. */
+	lvdcr0 = lvds->mode << LVDCR0_LVMD_SHIFT;
 	if (rcrtc->index == 2)
 		lvdcr0 |= LVDCR0_DUSEL;
 	rcar_lvds_write(lvds, LVDCR0, lvdcr0);
@@ -73,6 +70,10 @@ static void rcar_du_lvdsenc_start_gen2(s
 			LVDCR1_CHSTBY(3) | LVDCR1_CHSTBY(2) |
 			LVDCR1_CHSTBY(1) | LVDCR1_CHSTBY(0) | LVDCR1_CLKSTBY);
 
+	/* Enable LVDS operation and turn bias circuitry on. */
+	lvdcr0 |= LVDCR0_BEN | LVDCR0_LVEN;
+	rcar_lvds_write(lvds, LVDCR0, lvdcr0);
+
 	/*
 	 * Turn the PLL on, wait for the startup delay, and turn the output
 	 * on.