From: Cooper Chiou <cooper.chiou@xxxxxxxxx> commit 5662abf6e21338be6d085d6375d3732ac6147fd2 upstream. Tag code stored in bit7:5 for CTA block byte[3] is not the same as CEA extension block definition. Only check CEA block has basic audio support. v3: update commit message. Cc: stable@xxxxxxxxxxxxxxx Cc: Jani Nikula <jani.nikula@xxxxxxxxx> Cc: Shawn C Lee <shawn.c.lee@xxxxxxxxx> Cc: intel-gfx <intel-gfx@xxxxxxxxxxxxxxxxxxxxx> Signed-off-by: Cooper Chiou <cooper.chiou@xxxxxxxxx> Signed-off-by: Lee Shawn C <shawn.c.lee@xxxxxxxxx> Fixes: e28ad544f462 ("drm/edid: parse CEA blocks embedded in DisplayID") Reviewed-by: Jani Nikula <jani.nikula@xxxxxxxxx> Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx> Link: https://patchwork.freedesktop.org/patch/msgid/20220324061218.32739-1-shawn.c.lee@xxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/drm_edid.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/gpu/drm/drm_edid.c +++ b/drivers/gpu/drm/drm_edid.c @@ -4380,7 +4380,8 @@ bool drm_detect_monitor_audio(struct edi if (!edid_ext) goto end; - has_audio = ((edid_ext[3] & EDID_BASIC_AUDIO) != 0); + has_audio = (edid_ext[0] == CEA_EXT && + (edid_ext[3] & EDID_BASIC_AUDIO) != 0); if (has_audio) { DRM_DEBUG_KMS("Monitor has basic audio support\n");