Add a function to get the cea data block collection size.
Cc: Ville Syrjälä ville.syrjala@linux.intel.com Signed-off-by: Jani Nikula jani.nikula@intel.com --- drivers/gpu/drm/drm_edid.c | 24 +++++++++++++++++++++--- 1 file changed, 21 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c index c57f6333ea7d..002816509fc8 100644 --- a/drivers/gpu/drm/drm_edid.c +++ b/drivers/gpu/drm/drm_edid.c @@ -4482,6 +4482,20 @@ __cea_db_iter_current_block(const struct cea_db_iter *iter) return NULL; }
+/* + * References: + * - CTA-861-H section 7.3.3 CTA Extension Version 3 + */ +static int cea_db_collection_size(const u8 *cta) +{ + u8 d = cta[2]; + + if (d < 4 || d > 127) + return 0; + + return d - 4; +} + /* * References: * - VESA E-EDID v1.4 @@ -4492,15 +4506,19 @@ static const void *__cea_db_iter_edid_next(struct cea_db_iter *iter) const u8 *ext;
drm_edid_iter_for_each(ext, &iter->edid_iter) { + int size; + /* Only support CTA Extension revision 3+ */ if (ext[0] != CEA_EXT || cea_revision(ext) < 3) continue;
- iter->index = 4; - iter->end = ext[2]; - if (iter->end < 4 || iter->end > 127) + size = cea_db_collection_size(ext); + if (!size) continue;
+ iter->index = 4; + iter->end = iter->index + size; + return ext; }