From: Cooper Chiou <[email protected]>

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: [email protected]
Cc: Jani Nikula <[email protected]>
Cc: Shawn C Lee <[email protected]>
Cc: intel-gfx <[email protected]>
Signed-off-by: Cooper Chiou <[email protected]>
Signed-off-by: Lee Shawn C <[email protected]>
Fixes: e28ad544f462 ("drm/edid: parse CEA blocks embedded in DisplayID")
Reviewed-by: Jani Nikula <[email protected]>
Signed-off-by: Jani Nikula <[email protected]>
Link: 
https://patchwork.freedesktop.org/patch/msgid/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
 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
@@ -4776,7 +4776,8 @@ 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");


Reply via email to