Re: [PATCH v3 4/6] drm/bridge: tc358767: Disable MIPI_DSI_CLOCK_NON_CONTINUOUS

[Alexander Stein <alexander.stein@ew.tq-group.com>]

Am Montag, 24. Juni 2024, 09:45:13 CEST schrieb Alexander Stein:
> Hi,
> 
> Am Sonntag, 23. Juni 2024, 16:38:36 CEST schrieb Marek Vasut:
> > The MIPI_DSI_CLOCK_NON_CONTINUOUS causes visible artifacts in high
> > resolution modes, disable it. Namely, in DSI->DP mode 1920x1200 24
> > bpp 59.95 Hz, with DSI bus at maximum 1 Gbps per lane setting, the
> > image contains jittering empty lines.
> > 
> > Signed-off-by: Marek Vasut <marex@denx.de>
> 
> I can't see these artifacts in 1920x1200 24bpp, but still looks good to me
> Acked-by: Alexander Stein <alexander.stein@ew.tq-group.com>

I have to retract that. After checking for those mentioned artifacts
I noticed that the DP output was running without any issues.
There is something more going on here. Reverting this patch there wasn't
a single output problem.
This changes actually breaks my DSI connection randomly.
Sometimes it works, sometimes not. I also noticed that there wasn't even
a single DP link training failure, so I assume the DSI clock somehow
affected the internal state machine which even affected DP link training.
Until we know what's going on, NAK form me.

Best regards,
Alexander
> > ---
> > Cc: Andrzej Hajda <andrzej.hajda@intel.com>
> > Cc: Daniel Vetter <daniel@ffwll.ch>
> > Cc: David Airlie <airlied@gmail.com>
> > Cc: Jernej Skrabec <jernej.skrabec@gmail.com>
> > Cc: Jonas Karlman <jonas@kwiboo.se>
> > Cc: Laurent Pinchart <Laurent.pinchart@ideasonboard.com>
> > Cc: Lucas Stach <l.stach@pengutronix.de>
> > Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
> > Cc: Maxime Ripard <mripard@kernel.org>
> > Cc: Neil Armstrong <neil.armstrong@linaro.org>
> > Cc: Robert Foss <rfoss@kernel.org>
> > Cc: Thomas Zimmermann <tzimmermann@suse.de>
> > Cc: dri-devel@lists.freedesktop.org
> > Cc: kernel@dh-electronics.com
> > ---
> > V2: No change
> > V3: No change
> > ---
> >  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 c4e2455ad95e4..a48454fe2f634 100644
> > --- a/drivers/gpu/drm/bridge/tc358767.c
> > +++ b/drivers/gpu/drm/bridge/tc358767.c
> > @@ -2303,7 +2303,7 @@ static int tc_mipi_dsi_host_attach(struct tc_data *tc)
> >  	dsi->lanes = dsi_lanes;
> >  	dsi->format = MIPI_DSI_FMT_RGB888;
> >  	dsi->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_BURST |
> > -			  MIPI_DSI_MODE_LPM | MIPI_DSI_CLOCK_NON_CONTINUOUS;
> > +			  MIPI_DSI_MODE_LPM;
> >  
> >  	ret = devm_mipi_dsi_attach(dev, dsi);
> >  	if (ret < 0) {
> > 
> 
> 
> 


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