Add a helper for skipping the HDMI VSDB audio latency fields.
There's a functional change for HDMI VSDB blocks that do not respect the
spec: "I_Latency_Fields_Present shall be zero if Latency_Fields_Present
is zero". We assume this to hold when skipping the latency fields, and
ignore non-zero I_Latency_Fields_Present if Latency_Fields_Present is
zero.
Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx>
---
drivers/gpu/drm/drm_edid.c | 18 +++++++++++-------
1 file changed, 11 insertions(+), 7 deletions(-)
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 847076b29594..93067b8dd9f6 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -4695,6 +4695,16 @@ static bool hdmi_vsdb_i_latency_present(const u8 *db)
return hdmi_vsdb_latency_present(db) && db[8] & BIT(6);
}
+static int hdmi_vsdb_latency_length(const u8 *db)
+{
+ if (hdmi_vsdb_i_latency_present(db))
+ return 4;
+ else if (hdmi_vsdb_latency_present(db))
+ return 2;
+ else
+ return 0;
+}
+
/*
* do_hdmi_vsdb_modes - Parse the HDMI Vendor Specific data block
* @connector: connector corresponding to the HDMI sink
@@ -4720,13 +4730,7 @@ do_hdmi_vsdb_modes(struct drm_connector *connector, const u8 *db, u8 len)
if (!(db[8] & (1 << 5)))
goto out;
- /* Latency_Fields_Present */
- if (db[8] & (1 << 7))
- offset += 2;
-
- /* I_Latency_Fields_Present */
- if (db[8] & (1 << 6))
- offset += 2;
+ offset += hdmi_vsdb_latency_length(db);
/* the declared length is not long enough for the 2 first bytes
* of additional video format capabilities */
--
2.34.1
