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authorPhilipp Zabel <philipp.zabel@gmail.com>2022-01-23 11:16:52 +0100
committerJani Nikula <jani.nikula@intel.com>2022-01-24 15:36:33 +0100
commit2869f599c0d8c9c6492bec40d062951be8caae04 (patch)
tree4856a4f5ca30f987478470380fda7e7f3685b711 /drivers/gpu/drm/drm_edid.c
parentdrm/amdgpu: use ttm_resource_manager_debug (diff)
downloadlinux-2869f599c0d8c9c6492bec40d062951be8caae04.tar.xz
linux-2869f599c0d8c9c6492bec40d062951be8caae04.zip
drm/edid: support Microsoft extension for HMDs and specialized monitors
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.zabel@gmail.com> Reviewed-by: Jani Nikula <jani.nikula@intel.com> Signed-off-by: Jani Nikula <jani.nikula@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20220123101653.147333-1-philipp.zabel@gmail.com
Diffstat (limited to 'drivers/gpu/drm/drm_edid.c')
-rw-r--r--drivers/gpu/drm/drm_edid.c34
1 files changed, 34 insertions, 0 deletions
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))