Commit 118362a96286 ("drm/edid: Parse AMD Vendor-Specific Data Block")
added parsing of the AMD VSDB, but only for version 3 and only for the
replay/panel-type/luminance fields. Monitors that only advertise
FreeSync through a v1 or v2 AMD VSDB therefore get no variable refresh
rate range from the common EDID parser.Restructure drm_parse_amd_vsdb() and implement parsing for the FreeSync refresh range fields provided in the AMD VSDB. Additionally, version > 3 will be parsed as if they were version 3 (with a warning of this occurring) as future versions will likely be backwards compatible. Signed-off-by: Alex Huang <[email protected]> Reviewed-by: Mario Limonciello (AMD) <[email protected]> --- drivers/gpu/drm/drm_edid.c | 147 +++++++++++++++++++++++++++++------- include/drm/drm_connector.h | 22 +++++- 2 files changed, 139 insertions(+), 30 deletions(-) diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c index df3c25bac761..a12b5e6905fb 100644 --- a/drivers/gpu/drm/drm_edid.c +++ b/drivers/gpu/drm/drm_edid.c @@ -101,20 +101,42 @@ enum drm_edid_internal_quirk { #define MICROSOFT_IEEE_OUI 0xca125c #define AMD_IEEE_OUI 0x00001A +#define AMD_VSDB_V1_PAYLOAD_LEN 8 +#define AMD_VSDB_V2_PAYLOAD_LEN 13 #define AMD_VSDB_V3_PAYLOAD_MIN_LEN 15 -#define AMD_VSDB_V3_PAYLOAD_MAX_LEN 20 +#define AMD_VSDB_V3_PAYLOAD_MAX_LEN 21 -struct amd_vsdb_v3_payload { +#define AMD_VSDB_V3_MAX_VFREQ_EXT2_LEN 21 + +struct amd_vsdb_common_payload { u8 oui[3]; u8 version; +} __packed; + +struct amd_vsdb_v1_payload { + struct amd_vsdb_common_payload common; u8 feature_caps; - u8 rsvd0[3]; + u8 min_vfreq; + u8 max_vfreq; + u8 freesync_vcp_code; +} __packed; + +struct amd_vsdb_v2_payload { + struct amd_vsdb_v1_payload v1; u8 cs_eotf_support; u8 lum1_max; u8 lum1_min; u8 lum2_max; u8 lum2_min; - u8 rsvd1[2]; +} __packed; + +struct amd_vsdb_v3_payload { + struct amd_vsdb_v2_payload v2; + u8 max_vfreq_ext_low; + /* + * byte 14: bits 0-1 extend MSB of max refresh rate + */ + u8 max_vfreq_ext_high; /* * Bytes beyond AMD_VSDB_V3_PAYLOAD_MIN_LEN are optional; a * monitor may provide a payload as short as 15 bytes. Always @@ -123,6 +145,12 @@ struct amd_vsdb_v3_payload { u8 extra[AMD_VSDB_V3_PAYLOAD_MAX_LEN - AMD_VSDB_V3_PAYLOAD_MIN_LEN]; } __packed; +static const u8 amd_vsdb_min_len[] = { + [1] = AMD_VSDB_V1_PAYLOAD_LEN, + [2] = AMD_VSDB_V2_PAYLOAD_LEN, + [3] = AMD_VSDB_V3_PAYLOAD_MIN_LEN, +}; + struct detailed_mode_closure { struct drm_connector *connector; const struct drm_edid *drm_edid; @@ -5231,7 +5259,7 @@ static bool cea_db_is_microsoft_vsdb(const struct cea_db *db) static bool cea_db_is_amd_vsdb(const struct cea_db *db) { return cea_db_is_vendor(db, AMD_IEEE_OUI) && - cea_db_payload_len(db) >= AMD_VSDB_V3_PAYLOAD_MIN_LEN && + cea_db_payload_len(db) >= AMD_VSDB_V1_PAYLOAD_LEN && cea_db_payload_len(db) <= AMD_VSDB_V3_PAYLOAD_MAX_LEN; } @@ -6431,43 +6459,104 @@ static void drm_parse_microsoft_vsdb(struct drm_connector *connector, connector->base.id, connector->name, version, db[5]); } +static void drm_parse_amd_vsdb_common(struct drm_display_info *info, + const struct amd_vsdb_common_payload *data) +{ + info->amd_vsdb.version = data->version; +} + +static void drm_parse_amd_vsdb_v1(struct drm_display_info *info, + const struct amd_vsdb_v1_payload *data) +{ + info->amd_vsdb.freesync_supported = data->feature_caps & 0x1; + info->amd_vsdb.min_frame_rate = data->min_vfreq; + info->amd_vsdb.max_frame_rate = data->max_vfreq; + info->amd_vsdb.freesync_vcp_code = data->freesync_vcp_code; + + drm_parse_amd_vsdb_common(info, &data->common); +} + +static void drm_parse_amd_vsdb_v2(struct drm_display_info *info, + const struct amd_vsdb_v2_payload *data) +{ + info->amd_vsdb.luminance_range1.max_luminance = data->lum1_max; + info->amd_vsdb.luminance_range1.min_luminance = data->lum1_min; + info->amd_vsdb.luminance_range2.max_luminance = data->lum2_max; + info->amd_vsdb.luminance_range2.min_luminance = data->lum2_min; + + drm_parse_amd_vsdb_v1(info, &data->v1); +} + +static void drm_parse_amd_vsdb_v3(struct drm_display_info *info, + const struct amd_vsdb_v3_payload *data, + int payload_len) +{ + u16 max_frame_rate; + + info->amd_vsdb.replay_mode = data->v2.v1.feature_caps & 0x40; + info->amd_vsdb.panel_type = (data->v2.cs_eotf_support & 0xC0) >> 6; + + drm_parse_amd_vsdb_v2(info, &data->v2); + + /* vfreq is provided in a different set of fields for v3. */ + max_frame_rate = data->max_vfreq_ext_low | + (data->max_vfreq_ext_high & 0x3) << 8; + + /* + * The AMD VSDB v3 payload length is variable (15..21 bytes). + * All fields through max_vfreq_ext_high (byte 14) are always + * present, but data->extra[] (bytes 15+) may not be, so any access + * to extra[] must be guarded with a runtime length check to + * avoid out-of-bounds reads on shorter (but spec-valid) payloads. + */ + if (payload_len >= AMD_VSDB_V3_MAX_VFREQ_EXT2_LEN) + max_frame_rate |= (data->extra[5] & 0x3) << 10; + + info->amd_vsdb.max_frame_rate = max_frame_rate; +} + static void drm_parse_amd_vsdb(struct drm_connector *connector, const struct cea_db *db) { struct drm_display_info *info = &connector->display_info; const u8 *data = cea_db_data(db); - const struct amd_vsdb_v3_payload *p; + int payload_len = cea_db_payload_len(db); + u8 version; - p = (const struct amd_vsdb_v3_payload *)data; + version = ((const struct amd_vsdb_common_payload *)data)->version; - if (p->version != 0x03) { + if (version < 1) { drm_dbg_kms(connector->dev, "[CONNECTOR:%d:%s] Unsupported AMD VSDB version %u\n", - connector->base.id, connector->name, p->version); + connector->base.id, connector->name, version); return; } - info->amd_vsdb.version = p->version; - info->amd_vsdb.replay_mode = p->feature_caps & 0x40; - info->amd_vsdb.panel_type = (p->cs_eotf_support & 0xC0) >> 6; - info->amd_vsdb.luminance_range1.max_luminance = p->lum1_max; - info->amd_vsdb.luminance_range1.min_luminance = p->lum1_min; - info->amd_vsdb.luminance_range2.max_luminance = p->lum2_max; - info->amd_vsdb.luminance_range2.min_luminance = p->lum2_min; + if ((version <= 3 && payload_len < amd_vsdb_min_len[version]) || + (version > 3 && payload_len < AMD_VSDB_V3_PAYLOAD_MIN_LEN)) { + drm_dbg_kms(connector->dev, + "[CONNECTOR:%d:%s] AMD VSDB v%u payload too short (%d bytes)\n", + connector->base.id, connector->name, version, payload_len); + return; + } - /* - * The AMD VSDB v3 payload length is variable (15..20 bytes). - * All fields through p->rsvd1 (byte 14) are always present, - * but p->extra[] (bytes 15+) may not be. Any future access to - * extra[] must be guarded with a runtime length check to avoid - * out-of-bounds reads on shorter (but spec-valid) payloads. - * For example: - * - * int len = cea_db_payload_len(db); - * - * if (len > AMD_VSDB_V3_PAYLOAD_MIN_LEN) - * info->amd_vsdb.foo = p->extra[0]; - */ + switch (version) { + default: + drm_dbg_kms(connector->dev, + "[CONNECTOR:%d:%s] AMD VSDB v%u is unsupported, VSDB will be parsed as v3.\n", + connector->base.id, connector->name, version); + fallthrough; + case 3: + drm_parse_amd_vsdb_v3(info, (const struct amd_vsdb_v3_payload *)data, + payload_len); + break; + case 2: + drm_parse_amd_vsdb_v2(info, (const struct amd_vsdb_v2_payload *)data); + break; + case 1: + drm_parse_amd_vsdb_v1(info, (const struct amd_vsdb_v1_payload *)data); + break; + } } static void drm_parse_cea_ext(struct drm_connector *connector, diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h index 5f5ca023cd65..0914a2bd8ef1 100644 --- a/include/drm/drm_connector.h +++ b/include/drm/drm_connector.h @@ -697,7 +697,7 @@ enum drm_bus_flags { * struct drm_amd_vsdb_info - AMD-specific VSDB information * * This structure holds information parsed from the AMD Vendor-Specific Data - * Block (VSDB) version 3. + * Block (VSDB) versions 1 to 3. */ struct drm_amd_vsdb_info { /** @@ -705,6 +705,26 @@ struct drm_amd_vsdb_info { */ u8 version; + /** + * @freesync_supported: FreeSync (variable refresh rate) supported by panel + */ + bool freesync_supported; + + /** + * @min_frame_rate: FreeSync minimum refresh rate in Hz + */ + u16 min_frame_rate; + + /** + * @max_frame_rate: FreeSync maximum refresh rate in Hz + */ + u16 max_frame_rate; + + /** + * @freesync_vcp_code: MCCS VCP code for FreeSync + */ + u8 freesync_vcp_code; + /** * @replay_mode: Panel Replay supported */ -- 2.34.1
