From: Cooper Chiou <cooper.chiou@intel.com> stable inclusion from stable-v5.10.110 commit ba09b04173242c379d2442be979ab2f1971f2f8b bugzilla: https://gitee.com/openeuler/kernel/issues/I574AL Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- 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@vger.kernel.org Cc: Jani Nikula <jani.nikula@intel.com> Cc: Shawn C Lee <shawn.c.lee@intel.com> Cc: intel-gfx <intel-gfx@lists.freedesktop.org> Signed-off-by: Cooper Chiou <cooper.chiou@intel.com> Signed-off-by: Lee Shawn C <shawn.c.lee@intel.com> Fixes: e28ad544f462 ("drm/edid: parse CEA blocks embedded in DisplayID") Reviewed-by: Jani Nikula <jani.nikula@intel.com> Signed-off-by: Jani Nikula <jani.nikula@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20220324061218.32739-1-shawn.c... Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Yu Liao <liaoyu15@huawei.com> Reviewed-by: Wei Li <liwei391@huawei.com> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> --- drivers/gpu/drm/drm_edid.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c index 3d7593ea79f1..ce5a2ea38bc6 100644 --- a/drivers/gpu/drm/drm_edid.c +++ b/drivers/gpu/drm/drm_edid.c @@ -4806,7 +4806,8 @@ bool drm_detect_monitor_audio(struct edid *edid) 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"); -- 2.20.1