kernel/linux.git/drivers/gpu/drm/drm_displayid.c, branch linux-6.9.y

drm/displayid: provide access to DisplayID version and primary use case

2023-02-26T23:58:38+00:00

The DisplayID structure version and primary use case are stored in the DisplayID Base Section. We should be checking them in a number of places when parsing the DisplayID blocks. Currently, we completely ignore the primary use case, and just look at the block tags without cross-checking against structure version. Store the version and primary use case in the DisplayID iterator, and provide accessors to them. In general, the information is needed when iterating the blocks, and this is a convenient place to both store and retrieve the information during parsing. Promote using accessors rather than users poking at the iterator directly. Cc: Iaroslav Boliukin Cc: Dmitry Osipenko Signed-off-by: Jani Nikula Tested-by: Dmitry Osipenko Reviewed-by: Dmitry Osipenko Signed-off-by: Dmitry Osipenko Link: https://patchwork.freedesktop.org/patch/msgid/ad8a35c109f97ffe115e6b18e4a132b592f11089.1676580180.git.jani.nikula@intel.com

drm/displayid: return struct displayid_header from validate_displayid()

2023-02-26T23:58:38+00:00

Avoid figuring out the header pointer multiple times. Cc: Iaroslav Boliukin Cc: Dmitry Osipenko Signed-off-by: Jani Nikula Tested-by: Dmitry Osipenko Reviewed-by: Dmitry Osipenko Signed-off-by: Dmitry Osipenko Link: https://patchwork.freedesktop.org/patch/msgid/e840c744d165608a41db5a5e2bd4b0205783c697.1676580180.git.jani.nikula@intel.com

drm/displayid: add displayid_get_header() and check bounds better

2023-02-26T23:58:37+00:00

Add a helper to get a pointer to struct displayid_header. To be pedantic, add buffer overflow checks to not touch the base if that itself would overflow. Cc: Iaroslav Boliukin Cc: Dmitry Osipenko Signed-off-by: Jani Nikula Tested-by: Dmitry Osipenko Reviewed-by: Dmitry Osipenko Signed-off-by: Dmitry Osipenko Link: https://patchwork.freedesktop.org/patch/msgid/4a03b3a5132642d3cdb6d4c2641422955a917292.1676580180.git.jani.nikula@intel.com

drm/displayid: convert to drm_edid

2022-05-13T15:55:13+00:00

We'll need to propagate drm_edid everywhere. v2: Rebase Signed-off-by: Jani Nikula Reviewed-by: Ankit Nautiyal Link: https://patchwork.freedesktop.org/patch/msgid/a52a6882e87a4bb6b1670918f3aba13f9b52f6de.1652097712.git.jani.nikula@intel.com

drm/displayid: rename displayid_hdr to displayid_header

2021-03-31T12:42:39+00:00

Avoid any confusion with High Dynamic Range. No functional changes. Reviewed-by: Ville Syrjälä Signed-off-by: Jani Nikula Link: https://patchwork.freedesktop.org/patch/msgid/ce083bd2789c7e22a91710726162287db88e3f6c.1617024940.git.jani.nikula@intel.com

drm/displayid: allow data blocks with 0 payload length

2021-03-31T12:42:16+00:00

The DisplayID specifications explicitly call out 0 as a valid payload length for data blocks. The mere presence of a data block, or the information coded in the block specific data (bits 7:3 in offset 1), may be enough to convey the necessary information. Reviewed-by: Ville Syrjälä Signed-off-by: Jani Nikula Link: https://patchwork.freedesktop.org/patch/msgid/d562dff99ba7c92accb654a99b433bed471e8507.1617024940.git.jani.nikula@intel.com

drm/edid: use the new displayid iterator for tile info

2021-03-31T12:42:02+00:00

Neatly reduce displayid boilerplate in code. Remove excessive debug logging while at it, no other functional changes. The old displayid iterator becomes unused; remove it as well as make drm_find_displayid_extension() static. Reviewed-by: Ville Syrjälä Signed-off-by: Jani Nikula Link: https://patchwork.freedesktop.org/patch/msgid/fa4b5c790b5bdd82063545a6f209f8e9d78a63a7.1617024940.git.jani.nikula@intel.com

drm/displayid: add new displayid section/block iterators

2021-03-31T12:41:43+00:00

Iterating DisplayID blocks across sections (in EDID extensions) is unnecessarily complicated for the caller. Implement DisplayID iterators to go through all blocks in all sections. Usage example: const struct displayid_block *block; struct displayid_iter iter; displayid_iter_edid_begin(edid, &iter); displayid_iter_for_each(block, &iter) { /* operate on block */ } displayid_iter_end(&iter); When DisplayID is stored in EDID extensions, the DisplayID sections map to extensions as described in VESA DisplayID v1.3 Appendix B: DisplayID as an EDID Extension. This is implemented here. When DisplayID is stored in its dedicated DDC device 0xA4, according to VESA E-DDC v1.3, different rules apply for the structure. This is not implemented here, as we don't currently use it, but the idea is you'd have a different call for beginning the iteration, for example simply: displayid_iter_begin(displayid, &iter); instead of displayid_iter_edid_begin(), and everything else would be hidden away in the iterator functions. v2: - sizeof(struct displayid_block) -> sizeof(*block) (Ville) - remove __ prefix from displayid_iter_block Reviewed-by: Ville Syrjälä Signed-off-by: Jani Nikula Link: https://patchwork.freedesktop.org/patch/msgid/da3dead1752ab16c061f7bd248ac1a4268f7fefb.1617024940.git.jani.nikula@intel.com

drm/displayid: add separate drm_displayid.c

2021-03-31T12:41:35+00:00

We'll be adding more DisplayID specific functions going forward, so start off by splitting out a few functions to a separate file. We don't bother with exporting the functions; at least for now they should be needed solely within drm.ko. No functional changes. Reviewed-by: Ville Syrjälä Signed-off-by: Jani Nikula Link: https://patchwork.freedesktop.org/patch/msgid/07942d5011891b8e8f77245c78b34f4af97a9315.1617024940.git.jani.nikula@intel.com