Re: [igt-dev] [PATCH i-g-t] tests/kms_plane_alpha_blend: Fix a check in is_6bpc function

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Wed, Jul 14, 2021 at 11:21:47AM +0000, Srinivas, Vidya wrote:
> Hello Ville,
> 
> Apologies. I tried to turn off dithering from kernel itself. But still CRC mismatch came up.
> This is on Jasperlake chromebook which is using 6bpc panel.
> 
> Same jasperlake with 8bpc panel is working fine. 
> 
> So, as last resort we did this ☹.

Well that's a bit unfortunate because now the commit messages
are lying, and we still don't know what is going on.

Do the same failures happen with external DP @ 6bpc? I wouldn't
really expect any crc differences since AFAIK nothing in the pipe
should change before the dithering block, and with dithering disabled
the port should just chop off the extra bits at the very end.

> 
> Regards
> Vidya
> 
> -----Original Message-----
> From: Ville Syrjälä <ville.syrjala@linux.intel.com> 
> Sent: Wednesday, July 14, 2021 3:55 PM
> To: Srinivas, Vidya <vidya.srinivas@intel.com>
> Cc: igt-dev@lists.freedesktop.org
> Subject: Re: [igt-dev] [PATCH i-g-t] tests/kms_plane_alpha_blend: Fix a check in is_6bpc function
> 
> On Wed, Jul 14, 2021 at 01:30:02PM +0530, Vidya Srinivas wrote:
> > Fixes commit 3bf28f9dffd41b85c262d4e6664ffbdf5b7d9a93.
> > 
> > is_6bpc is supposed to return false if connector is not eDP or DSI.
> > The right check will be DRM_MODE_CONNECTOR_eDP && 
> > DRM_MODE_CONNECTOR_DSI By mistake DRM_MODE_CONNECTOR_eDP || 
> > DRM_MODE_CONNECTOR_DSI was being used.
> 
> Instead of these incomplete hacks why aren't we just turning off dithering when doing crc capture?
> 
> > 
> > Credits-to: Ashutosh Dixit <ashutosh.dixit@intel.com>
> > Signed-off-by: Vidya Srinivas <vidya.srinivas@intel.com>
> > ---
> >  tests/kms_plane_alpha_blend.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/tests/kms_plane_alpha_blend.c 
> > b/tests/kms_plane_alpha_blend.c index a3529dc2190f..8020216c1594 
> > 100644
> > --- a/tests/kms_plane_alpha_blend.c
> > +++ b/tests/kms_plane_alpha_blend.c
> > @@ -454,7 +454,7 @@ static bool is_6bpc(igt_display_t *display, enum pipe pipe) {
> >  		return false;
> >  
> >  	c = output->config.connector;
> > -	if (c->connector_type != DRM_MODE_CONNECTOR_eDP ||
> > +	if (c->connector_type != DRM_MODE_CONNECTOR_eDP &&
> >  		c->connector_type != DRM_MODE_CONNECTOR_DSI)
> >  		return false;
> >  
> > --
> > 2.32.0
> > 
> > _______________________________________________
> > igt-dev mailing list
> > igt-dev@lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/igt-dev
> 
> --
> Ville Syrjälä
> Intel

-- 
Ville Syrjälä
Intel
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