linux-kernel - Re: [PATCH v2 6/7] drm/tests: hdmi: Add limited range tests for YUV420 mode

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250314-didactic-bandicoot-of-perspective-e077ae@houat>
Date: Fri, 14 Mar 2025 14:52:42 +0100
From: Maxime Ripard <mripard@...nel.org>
To: Cristian Ciocaltea <cristian.ciocaltea@...labora.com>
Cc: Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>, 
	Thomas Zimmermann <tzimmermann@...e.de>, David Airlie <airlied@...il.com>, 
	Simona Vetter <simona@...ll.ch>, Dave Stevenson <dave.stevenson@...pberrypi.com>, 
	Dmitry Baryshkov <dmitry.baryshkov@...aro.org>, kernel@...labora.com, dri-devel@...ts.freedesktop.org, 
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 6/7] drm/tests: hdmi: Add limited range tests for
 YUV420 mode

On Wed, Mar 12, 2025 at 12:54:51AM +0200, Cristian Ciocaltea wrote:
> On 3/11/25 6:17 PM, Maxime Ripard wrote:
> > On Tue, Mar 11, 2025 at 12:57:38PM +0200, Cristian Ciocaltea wrote:
> >> Provide tests to verify that drm_atomic_helper_connector_hdmi_check()
> >> helper behaviour when using YUV420 output format is to always set the
> >> limited RGB quantization range to 'limited', no matter what the value of
> >> Broadcast RGB property is.
> 
> [...]
> 
> > We need more tests than that to test the various combinations, whether
> > the fallback to YUV420 should work or not depending on the EDID, the
> > driver capabilities, YUV420-only vs YUV420-also, etc.
> 
> Some fallback tests were provided in the next patch, including checks like:
> 
>   KUNIT_ASSERT_TRUE(test, drm_mode_is_420_only(info, yuv420_only_mode));
>   KUNIT_ASSERT_TRUE(test, drm_mode_is_420_also(info, preferred));
> 
> I'll try to further extend the test coverage.

Yeah, sorry, I saw them after reviewing this patch. Still, I think we'll
need more, especially to deal with the fallback cases. IIRC, you were
testing the cases where you're forced to take YUV420 because of the
monitors (or drivers) limit, but we should also try the tests where
you're forced to take YUV420 but the driver implements HDMI 1.4 only for
example, and thus we can't.

Maxime

Download attachment "signature.asc" of type "application/pgp-signature" (274 bytes)