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From: Tomi Valkeinen <tomi.valkeinen@ti.com>
To: dri-devel@lists.freedesktop.org,
	Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Alejandro Hernandez <ajhernandez@ti.com>,
	Tomi Valkeinen <tomi.valkeinen@ti.com>,
	Jyri Sarha <jsarha@ti.com>
Subject: [PATCHv2 3/7] drm/omap: tweak HDMI DDC timings
Date: Mon, 30 Sep 2019 13:38:36 +0300	[thread overview]
Message-ID: <20190930103840.18970-4-tomi.valkeinen@ti.com> (raw)
In-Reply-To: <20190930103840.18970-1-tomi.valkeinen@ti.com>

From: Alejandro Hernandez <ajhernandez@ti.com>

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>
---
 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 */
-- 
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Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki

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  parent reply	other threads:[~2019-09-30 10:38 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-09-30 10:38 [PATCHv2 0/7] drm/omap: misc improvements Tomi Valkeinen
2019-09-30 10:38 ` [PATCHv2 1/7] drm/omap: drop unneeded locking from mgr_fld_write() Tomi Valkeinen
2019-09-30 10:38 ` [PATCHv2 2/7] drm/omap: avoid copy in mgr_fld_read/write Tomi Valkeinen
2019-10-04  7:02   ` Laurent Pinchart
2019-09-30 10:38 ` Tomi Valkeinen [this message]
2019-09-30 10:38 ` [PATCHv2 4/7] drm/omap: fix missing scaler pixel fmt limitations Tomi Valkeinen
2019-09-30 10:38 ` [PATCHv2 5/7] drm/omap: dss: move platform_register_drivers() to dss.c and remove core.c Tomi Valkeinen
2019-09-30 10:38 ` [PATCHv2 6/7] drm/omap: hdmi5: automatically choose limited/full range output Tomi Valkeinen
2019-09-30 10:38 ` [PATCHv2 7/7] drm/omap: hdmi4: fix use of uninitialized var Tomi Valkeinen
2019-10-04  7:03   ` Laurent Pinchart
2019-10-08 14:13   ` Tony Lindgren
2019-10-08 14:16     ` Tomi Valkeinen
2019-10-08 14:21       ` Tony Lindgren
2019-10-10  6:47         ` Tomi Valkeinen
2019-10-10 13:24           ` Tony Lindgren
2019-10-11 10:25             ` Tomi Valkeinen
2019-10-11 16:10               ` Tony Lindgren

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