From 56e8602152ea13404e0bcff9c0017d34abc44e76 Mon Sep 17 00:00:00 2001
From: David Jander <david@protonic.nl>
Date: Fri, 21 Jul 2023 18:53:28 +0200
Subject: drm/bridge: tc358767: give VSDELAY some positive value
Git-commit: 85a241cb128ac449b301d5b7da16a7c11f5fc094
Patch-mainline: v6.6-rc1
References: jsc#PED-3527 jsc#PED-5475 jsc#PED-6068 jsc#PED-6070 jsc#PED-6116 jsc#PED-6120 jsc#PED-5065 jsc#PED-5477 jsc#PED-5511 jsc#PED-6041 jsc#PED-6069 jsc#PED-6071
The documentation is not clear about how this delay works.
Empirical tests have shown that with a VSDELAY of 0, the first
scanline is not properly formatted in the output stream when
DSI->DP mode is used. The calculation spreadsheets from Toshiba
seem to always make this value equal to the HFP + 10 for DSI->DP
use-case. For DSI->DPI this value should be > 2 and for DPI->DP
it seems to always be 0x64.
Signed-off-by: David Jander <david@protonic.nl>
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Tested-by: Marek Vasut <marex@denx.de> # TC9595
Reviewed-by: Marek Vasut <marex@denx.de>
Signed-off-by: Marek Vasut <marex@denx.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20230721165328.3968759-2-l.stach@pengutronix.de
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/bridge/tc358767.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/bridge/tc358767.c b/drivers/gpu/drm/bridge/tc358767.c
index 40d52f6f073c..b45bffab7c81 100644
--- a/drivers/gpu/drm/bridge/tc358767.c
+++ b/drivers/gpu/drm/bridge/tc358767.c
@@ -817,7 +817,7 @@ static int tc_set_common_video_mode(struct tc_data *tc,
* sync signals
*/
ret = regmap_write(tc->regmap, VPCTRL0,
- FIELD_PREP(VSDELAY, 0) |
+ FIELD_PREP(VSDELAY, right_margin + 10) |
OPXLFMT_RGB888 | FRMSYNC_DISABLED | MSF_DISABLED);
if (ret)
return ret;
--
2.43.0