From 1ee3e217f98e4a14a792ed2d7b42417ad1194922 Mon Sep 17 00:00:00 2001 From: Jani Nikula Date: Wed, 4 Jan 2023 12:05:24 +0200 Subject: drm/edid: fix and clarify HDMI VSDB audio latency parsing MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add helpers for Latency_Fields_Present and I_Latency_Fields_Present bits, and fix the parsing: - Respect specification regarding "I_Latency_Fields_Present shall be zero if Latency_Fields_Present is zero". - Don't claim latency fields are present if the data block isn't big enough to hold them. Cc: Ville Syrjälä Signed-off-by: Jani Nikula Reviewed-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/80426772a2d2e17bebf6f58d99b7d0cf6260c2d6.1672826282.git.jani.nikula@intel.com --- drivers/gpu/drm/drm_edid.c | 27 +++++++++++++++++++-------- 1 file changed, 19 insertions(+), 8 deletions(-) (limited to 'drivers/gpu/drm/drm_edid.c') diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c index 076ba125c38d..847076b29594 100644 --- a/drivers/gpu/drm/drm_edid.c +++ b/drivers/gpu/drm/drm_edid.c @@ -4685,6 +4685,16 @@ static int add_3d_struct_modes(struct drm_connector *connector, u16 structure, return modes; } +static bool hdmi_vsdb_latency_present(const u8 *db) +{ + return db[8] & BIT(7); +} + +static bool hdmi_vsdb_i_latency_present(const u8 *db) +{ + return hdmi_vsdb_latency_present(db) && db[8] & BIT(6); +} + /* * do_hdmi_vsdb_modes - Parse the HDMI Vendor Specific data block * @connector: connector corresponding to the HDMI sink @@ -5357,6 +5367,7 @@ drm_parse_hdr_metadata_block(struct drm_connector *connector, const u8 *db) } } +/* HDMI Vendor-Specific Data Block (HDMI VSDB, H14b-VSDB) */ static void drm_parse_hdmi_vsdb_audio(struct drm_connector *connector, const u8 *db) { @@ -5364,18 +5375,18 @@ drm_parse_hdmi_vsdb_audio(struct drm_connector *connector, const u8 *db) if (len >= 6 && (db[6] & (1 << 7))) connector->eld[DRM_ELD_SAD_COUNT_CONN_TYPE] |= DRM_ELD_SUPPORTS_AI; - if (len >= 8) { - connector->latency_present[0] = db[8] >> 7; - connector->latency_present[1] = (db[8] >> 6) & 1; - } - if (len >= 9) + + if (len >= 10 && hdmi_vsdb_latency_present(db)) { + connector->latency_present[0] = true; connector->video_latency[0] = db[9]; - if (len >= 10) connector->audio_latency[0] = db[10]; - if (len >= 11) + } + + if (len >= 12 && hdmi_vsdb_i_latency_present(db)) { + connector->latency_present[1] = true; connector->video_latency[1] = db[11]; - if (len >= 12) connector->audio_latency[1] = db[12]; + } drm_dbg_kms(connector->dev, "[CONNECTOR:%d:%s] HDMI: latency present %d %d, video latency %d %d, audio latency %d %d\n", -- cgit