19da408ab4
[ Upstream commit 75478b3b393bcbdca4e6da76fe3a9f1a4133ec5d ]
The current code, when parsing the EDID Deep Color depths, that the
YUV422 cannot be used, referring to the HDMI 1.3 Specification.
This specification, in its section 6.2.4, indeed states:
For each supported Deep Color mode, RGB 4:4:4 shall be supported and
optionally YCBCR 4:4:4 may be supported.
YCBCR 4:2:2 is not permitted for any Deep Color mode.
This indeed can be interpreted like the code does, but the HDMI 1.4
specification further clarifies that statement in its section 6.2.4:
For each supported Deep Color mode, RGB 4:4:4 shall be supported and
optionally YCBCR 4:4:4 may be supported.
YCBCR 4:2:2 is also 36-bit mode but does not require the further use
of the Deep Color modes described in section 6.5.2 and 6.5.3.
This means that, even though YUV422 can be used with 12 bit per color,
it shouldn't be treated as a deep color mode.
This is also broken with YUV444 if it's supported by the display, but
DRM_EDID_HDMI_DC_Y444 isn't set. In such a case, the code will clear
color_formats of the YUV444 support set previously in
drm_parse_cea_ext(), but will not set it back.
Since the formats supported are already setup properly in
drm_parse_cea_ext(), let's just remove the code modifying the formats in
drm_parse_hdmi_deep_color_info()
Fixes: d0c94692e0a3 ("drm/edid: Parse and handle HDMI deep color modes.")
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220120151625.594595-3-maxime@cerno.tech
Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.