diff mbox series

[v2,2/2] drm/bridge: tc358767: give VSDELAY some positive value

Message ID 20230721165328.3968759-2-l.stach@pengutronix.de (mailing list archive)
State New, archived
Headers show
Series [v2,1/2] drm/bridge: tc358767: increase PLL lock time delay | expand

Commit Message

Lucas Stach July 21, 2023, 4:53 p.m. UTC 
From: David Jander <david@protonic.nl>

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>
---
 drivers/gpu/drm/bridge/tc358767.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Marek Vasut July 21, 2023, 7:19 p.m. UTC | #1 
On 7/21/23 18:53, Lucas Stach wrote:
> From: David Jander <david@protonic.nl>
> 
> 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>

Applied both to drm-misc-next , thanks !
diff mbox series

Patch

diff --git a/drivers/gpu/drm/bridge/tc358767.c b/drivers/gpu/drm/bridge/tc358767.c
index 29721e26de5d..5c33f13fdb39 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;