From 157d8f60363a7c5767fdda81fea946b44945454f Mon Sep 17 00:00:00 2001
From: Alejandro Hernandez <ajhernandez@ti.com>
Date: Mon, 30 Sep 2019 13:38:36 +0300
Subject: drm/omap: tweak HDMI DDC timings
Git-commit: 157d8f60363a7c5767fdda81fea946b44945454f
Patch-mainline: v5.5-rc1
References: bsc#1152489
A "HDMI I2C Master Error" is sometimes reported with the current DDC SCL
timings. The current settings for a 10us SCL period (100 KHz) causes the
error with some displays. This patch increases the SCL signal period
from 10us to 10.2us, with the new settings the error is not observed
Signed-off-by: Alejandro Hernandez <ajhernandez@ti.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190930103840.18970-4-tomi.valkeinen@ti.com
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
---
drivers/gpu/drm/omapdrm/dss/hdmi5_core.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/omapdrm/dss/hdmi5_core.c b/drivers/gpu/drm/omapdrm/dss/hdmi5_core.c
index 7400fb99d453..4c588ec7634a 100644
--- a/drivers/gpu/drm/omapdrm/dss/hdmi5_core.c
+++ b/drivers/gpu/drm/omapdrm/dss/hdmi5_core.c
@@ -39,8 +39,8 @@ static void hdmi_core_ddc_init(struct hdmi_core_data *core)
{
void __iomem *base = core->base;
const unsigned long long iclk = 266000000; /* DSS L3 ICLK */
- const unsigned int ss_scl_high = 4600; /* ns */
- const unsigned int ss_scl_low = 5400; /* ns */
+ const unsigned int ss_scl_high = 4700; /* ns */
+ const unsigned int ss_scl_low = 5500; /* ns */
const unsigned int fs_scl_high = 600; /* ns */
const unsigned int fs_scl_low = 1300; /* ns */
const unsigned int sda_hold = 1000; /* ns */
--
2.28.0