On 6/2/23 21:15, Lucas Stach wrote:
From: David Jander <david@xxxxxxxxxxx> 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@xxxxxxxxxxx> Signed-off-by: Lucas Stach <l.stach@xxxxxxxxxxxxxx> --- 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 46916ae30f8f..9f2c67b4a488 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;
Aren't you running into a problem due to VS timing misconfiguration on the scanout engine or DSI serializer side ? The VSDELAY seems to increase the length of VSYNC active . Which DSI bus mode do you use, sync events/pulses/burst ?
