drm/edid: Handle EDID 1.4 range descriptor h/vfreq offsets

EDID 1.4 introduced some extra flags in the range
descriptor to support min/max h/vfreq >= 255. Consult them
to correctly parse the vfreq limits.

Note that some combinations of the flags are documented
as "reserved" (as are some other values in the descriptor)
but explicitly checking for those doesn't seem particularly
worthwile since we end up with bogus results whether we
decode them or not.

v2: Increase the storage to u16 to make it work (Jani)
    Note the "reserved" values situation (Jani)
v3: Document the EDID version number in the defines
    Drop some bogus (u8) casts

Cc: stable@vger.kernel.org
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/6519
References: https://gitlab.freedesktop.org/drm/intel/-/issues/6484
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220826213501.31490-2-ville.syrjala@linux.intel.com
Reviewed-by: Manasi Navare <manasi.d.navare@intel.com>
This commit is contained in:
Ville Syrjälä
2022-08-27 00:34:51 +03:00
parent a3f7c10a26
commit c7943bb324
4 changed files with 27 additions and 10 deletions

View File

@@ -319,8 +319,8 @@ enum drm_panel_orientation {
* EDID's detailed monitor range
*/
struct drm_monitor_range_info {
u8 min_vfreq;
u8 max_vfreq;
u16 min_vfreq;
u16 max_vfreq;
};
/**

View File

@@ -92,6 +92,11 @@ struct detailed_data_string {
u8 str[13];
} __attribute__((packed));
#define DRM_EDID_RANGE_OFFSET_MIN_VFREQ (1 << 0) /* 1.4 */
#define DRM_EDID_RANGE_OFFSET_MAX_VFREQ (1 << 1) /* 1.4 */
#define DRM_EDID_RANGE_OFFSET_MIN_HFREQ (1 << 2) /* 1.4 */
#define DRM_EDID_RANGE_OFFSET_MAX_HFREQ (1 << 3) /* 1.4 */
#define DRM_EDID_DEFAULT_GTF_SUPPORT_FLAG 0x00
#define DRM_EDID_RANGE_LIMITS_ONLY_FLAG 0x01
#define DRM_EDID_SECONDARY_GTF_SUPPORT_FLAG 0x02