The CTA Data Block Collection is valid only for CTA extension version
3. In versions 1 and 2, it is a reserved block, which we ignore.
The DTD start offset (byte 2, or d in CTA-861 spec), which determines
the CTA Data Block Collection size, is specified slightly differently
for different versions:
Version 1:
d = offset for the byte following the reserved data block. If no
data is provided in the reserved data block, then d=4. If no DTDs
are provided, then d=0
Version 2:
d = offset for the byte following the reserved data block. If no
data is provided in the reserved data block, then d=4. If d=0, then
no detailed timing descriptors are provided, and no data is provided
in the reserved data block.
Version 3:
d = offset for the byte following the data block collection. If no
data is provided in the data block collection, then d=4. If d=0,
then no detailed timing descriptors are provided, and no data is
provided in the data block collection.
Ever since commit 9e50b9d55e ("drm: edid: Add some bounds checking"),
we've interpreted 0 to mean there are no DTDs but it's all Data
Blocks. Per the spec, Data Blocks are only valid for version 3, where we
should interpret 0 to mean there are no data blocks.
Follow the spec (and hope the EDIDs follow it too).
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/2a4c94417f024cbafc5d4ca0a74e4617fc4325d1.1654674560.git.jani.nikula@intel.com
We'll need to propagate drm_edid everywhere. This is a clunky start, but
a start nonetheless. We'll eventually convert all of the EDID parsing to
struct drm_edid.
Initially, we'll just create the struct drm_edid in stack. This will be
the compat layer for legacy struct edid code. In the future, we'll have
EDID read return drm_edid objects.
v2: Add legacy init helper.
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/000452fddedbaf7f473ac25d4dde2502e60b8e39.1652097712.git.jani.nikula@intel.com
Introduce new opaque type struct drm_edid to encapsulate the EDID data
and the size allocated for it. The contents will be private to
drm_edid.c.
There are a number of reasons for adding a container around struct edid:
* struct edid is a raw blob pointer to data that usually originates
outside of the kernel. Its size is contained within the structure.
* There's no way to attach meta information (such as allocated memory
size) to struct edid.
* Validation of the EDID blob and its size become crucial, and it's
spread all over the subsystem, with varying levels of accuracy.
* HDMI Forum has introduced an HF-EEODB extension that defines an
override EDID size within an EDID extension. The size allocated for an
EDID depends on whether the allocator understands the HF-EEODB
extension. Given a struct edid *, it's impossible to know how much
memory was actually allocated for it.
There are also some reasons for making the container type struct
drm_edid opaque and private to drm_edid.c:
* Have only one place for creating and parsing the EDID, to avoid
duplicating bugs.
* Prepare for reading a pure DisplayID 2.0 from its own DDC address, and
adding it within the same struct drm_edid container, transparently,
and for all drivers.
* With the idea that the drm_edid objects are immutable during their
lifetimes, it will be possible to refcount them and reduce EDID
copying everywhere (this is left for future work).
Initially, just add the type. In follow-up, we'll start converting the
guts of drm_edid.c to use it, and finally add interfaces around it.
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/f3ecabd8a219aea678ad00f7bcdecf77b27b3c78.1652097712.git.jani.nikula@intel.com
Convert drm_find_cea_extension() to a predicate function to check if the
EDID has a CTA extension or a DisplayID CTA data block. This is mainly
to avoid adding new users that only find the first CTA extension.
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/a5bf228942e6bd0fc70d5cf7a14c249a14a7afcd.1651569697.git.jani.nikula@intel.com
The DisplayID CTA data block version does not necessarily match the CTA
revision. Simplify by postponing drm_edid_to_eld() slightly, and reusing
the CTA revision extracted by drm_parse_cea_ext().
By not bailing out early in drm_edid_to_eld() we may end up filling
meaningless data to the ELD. However, the main decision for audio is not
the ELD, but rather drm_detect_monitor_audio() called by drivers.
(Arguably a future cleanup could do that in drm_add_edid_modes() and
cache the result in the connector.)
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/163ebbfd765066acbfc267256fb3b67fc711a78d.1651569697.git.jani.nikula@intel.com
Convert drm_find_cea_extension() to EDID block iterator in color format
and CTA revision detection. Detect them in all CTA extensions.
Also parse CTA Data Blocks in DisplayID even if there's no CTA EDID
extension.
v2:
- Don't assume DRM_COLOR_FORMAT_RGB444 support if there's only DisplayID
CTA Data Blocks (Ville)
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220505105242.1198521-1-jani.nikula@intel.com
Iterate through all CTA data blocks across all CTA extensions and
DisplayID data blocks. This may gather more data than before, and if
there's duplicated data, some is overwritten by whichever comes last.
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/8bdc67aa731857111eddd08a9c192d41d40b5f5a.1651569697.git.jani.nikula@intel.com
Abstract helpers for matching vendor data blocks and extended tags, and
use them to simplify all the cea_db_is_*() functions.
Take void pointer as parameter to allow transitional use for both u8 *
and struct cea_db *.
v2: Remove superfluous parens (Ville)
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/b6bb813afc35c763e744c6cdb4a787da3adf910b.1651569697.git.jani.nikula@intel.com
Find HF-SCDB information in CEA extensions block. And retrieve
Max_TMDS_Character_Rate that support by sink device.
v2: HF-SCDB and HF-VSDBS carry the same SCDS data. Reuse
drm_parse_hdmi_forum_vsdb() to parse this packet.
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
Cc: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Cc: intel-gfx <intel-gfx@lists.freedesktop.org>
Signed-off-by: Lee Shawn C <shawn.c.lee@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/2bf7110cdb56d5dda311480787faf472c9802de4.1651569697.git.jani.nikula@intel.com
