The LG 32GN600 monitor (PNP ID GSM 0x7766) advertises HDR support in its CTA-861 Extension block with SMPTE ST 2084 (PQ) EOTF support (byte 0x9e = 0x05) and valid desired content luminance descriptors (351 cd/m^2 max CLL/FALL at bytes 0xa0-0xa2).
However, due to a factory firmware bug, the HDR Static Metadata Data Block descriptor byte (byte 0x9f) is reported as 0x00 instead of 0x01, omitting the Static Metadata Type 1 capability bit (bit 0). Because of this omitted bit, drm_parse_hdr_metadata_block() sets metadata_type to 0. Consequently, drm_calculate_luminance_range() rejects the block, and userspace attempts to perform atomic KMS commits configuring HDR output metadata fail with -EINVAL (Error 22), preventing compositors (Plasma, Gamescope, MPV) from engaging HDR on this display. Introduce EDID_QUIRK_FORCE_HDR_STATIC_METADATA_TYPE1 to force the Static Metadata Type 1 descriptor bit for displays with this defective EDID block, and register the LG 32GN600 (GSM 0x7766) in the EDID quirk table. Signed-off-by: Xela <[email protected]> --- v2: - Specify LG 32GN600 model in subject, commit description, and code comment. drivers/gpu/drm/drm_edid.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c index 07970e5b5..b467a643a 100644 --- a/drivers/gpu/drm/drm_edid.c +++ b/drivers/gpu/drm/drm_edid.c @@ -96,6 +96,8 @@ enum drm_edid_internal_quirk { EDID_QUIRK_NON_DESKTOP, /* Cap the DSC target bitrate to 15bpp */ EDID_QUIRK_CAP_DSC_15BPP, + /* Force Static Metadata Type 1 for HDR Static Metadata Data Block */ + EDID_QUIRK_FORCE_HDR_STATIC_METADATA_TYPE1, }; #define MICROSOFT_IEEE_OUI 0xca125c @@ -195,6 +197,9 @@ static const struct edid_quirk { /* LG 27GN950 */ EDID_QUIRK('G', 'S', 'M', 0x5b9a, BIT(EDID_QUIRK_CAP_DSC_15BPP)), + /* LG 32GN600 */ + EDID_QUIRK('G', 'S', 'M', 0x7766, BIT(EDID_QUIRK_FORCE_HDR_STATIC_METADATA_TYPE1)), + /* LGD panel of HP zBook 17 G2, eDP 10 bpc, but reports unknown bpc */ EDID_QUIRK('L', 'G', 'D', 764, BIT(EDID_QUIRK_FORCE_10BPC)), @@ -5498,6 +5503,10 @@ drm_parse_hdr_metadata_block(struct drm_connector *connector, const u8 *db) hdr_metadata->eotf = eotf_supported(db); hdr_metadata->metadata_type = hdr_metadata_type(db); + if (drm_edid_has_internal_quirk(connector, + EDID_QUIRK_FORCE_HDR_STATIC_METADATA_TYPE1)) + hdr_metadata->metadata_type |= BIT(HDMI_STATIC_METADATA_TYPE1); + if (len >= 4) hdr_metadata->max_cll = db[4]; if (len >= 5) -- 2.54.0
