Add minimal support for parsing VSDBs documented in Microsoft's "EDID extension for head-mounted and specialized monitors" [1]. The version field and the desktop usage flag can be used to set the non_desktop connector property.
[1] https://docs.microsoft.com/en-us/windows-hardware/drivers/display/specialized-monitors-edid-extension Tested with HPN-36C1 and LEN-B800. Signed-off-by: Philipp Zabel <philipp.za...@gmail.com> Reviewed-by: Jani Nikula <jani.nik...@intel.com> --- Changes since v1 [2]: - Split out quirk removal into a separate patch. - Set non_desktop to true instead of 1. [2] https://lore.kernel.org/all/20211213184706.5776-1-philipp.za...@gmail.com/ --- drivers/gpu/drm/drm_edid.c | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c index 12893e7be89b..271b5616cfaf 100644 --- a/drivers/gpu/drm/drm_edid.c +++ b/drivers/gpu/drm/drm_edid.c @@ -93,6 +93,8 @@ static int oui(u8 first, u8 second, u8 third) /* Non desktop display (i.e. HMD) */ #define EDID_QUIRK_NON_DESKTOP (1 << 12) +#define MICROSOFT_IEEE_OUI 0xca125c + struct detailed_mode_closure { struct drm_connector *connector; struct edid *edid; @@ -4222,6 +4224,17 @@ static bool cea_db_is_hdmi_forum_vsdb(const u8 *db) return oui(db[3], db[2], db[1]) == HDMI_FORUM_IEEE_OUI; } +static bool cea_db_is_microsoft_vsdb(const u8 *db) +{ + if (cea_db_tag(db) != VENDOR_BLOCK) + return false; + + if (cea_db_payload_len(db) != 21) + return false; + + return oui(db[3], db[2], db[1]) == MICROSOFT_IEEE_OUI; +} + static bool cea_db_is_vcdb(const u8 *db) { if (cea_db_tag(db) != USE_EXTENDED_TAG) @@ -5149,6 +5162,25 @@ drm_parse_hdmi_vsdb_video(struct drm_connector *connector, const u8 *db) drm_parse_hdmi_deep_color_info(connector, db); } +/* + * See EDID extension for head-mounted and specialized monitors, specified at: + * https://docs.microsoft.com/en-us/windows-hardware/drivers/display/specialized-monitors-edid-extension + */ +static void drm_parse_microsoft_vsdb(struct drm_connector *connector, + const u8 *db) +{ + struct drm_display_info *info = &connector->display_info; + u8 version = db[4]; + bool desktop_usage = db[5] & BIT(6); + + /* Version 1 and 2 for HMDs, version 3 flags desktop usage explicitly */ + if (version == 1 || version == 2 || (version == 3 && !desktop_usage)) + info->non_desktop = true; + + drm_dbg_kms(connector->dev, "HMD or specialized display VSDB version %u: 0x%02x\n", + version, db[5]); +} + static void drm_parse_cea_ext(struct drm_connector *connector, const struct edid *edid) { @@ -5179,6 +5211,8 @@ static void drm_parse_cea_ext(struct drm_connector *connector, drm_parse_hdmi_vsdb_video(connector, db); if (cea_db_is_hdmi_forum_vsdb(db)) drm_parse_hdmi_forum_vsdb(connector, db); + if (cea_db_is_microsoft_vsdb(db)) + drm_parse_microsoft_vsdb(connector, db); if (cea_db_is_y420cmdb(db)) drm_parse_y420cmdb_bitmap(connector, db); if (cea_db_is_vcdb(db)) base-commit: e783362eb54cd99b2cac8b3a9aeac942e6f6ac07 -- 2.34.1
