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@xxxxxxxxxxxxxxxxxx>
---
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.
