From:   Kai-Heng Feng <kai.heng.feng@canonical.com>
To:     tiwai@suse.com
Cc:     Kai-Heng Feng <kai.heng.feng@canonical.com>,
        Jaroslav Kysela <perex@perex.cz>,
        Kai Vehmanen <kai.vehmanen@linux.intel.com>,
        Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>,
        Ranjani Sridharan <ranjani.sridharan@linux.intel.com>,
        Hui Wang <hui.wang@canonical.com>, alsa-devel@alsa-project.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH] ALSA: hda/hdmi: Consider ELD is invalid when no SAD is present
Date:   Thu,  2 Dec 2021 15:33:35 +0800
Message-Id: <20211202073338.1384768-1-kai.heng.feng@canonical.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

There's a system that reports a bogus HDMI audio interface:
$ cat eld#2.0
monitor_present         1
eld_valid               1
monitor_name
connection_type         DisplayPort
eld_version             [0x2] CEA-861D or below
edid_version            [0x3] CEA-861-B, C or D
manufacture_id          0xe430
product_id              0x690
port_id                 0x0
support_hdcp            0
support_ai              0
audio_sync_delay        0
speakers                [0xffff] FL/FR LFE FC RL/RR RC FLC/FRC RLC/RRC FLW/FRW FLH/FRH TC FCH
sad_count               0

Since playing audio is not possible without SAD, also consider ELD is
invalid for this case.

Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
---
 sound/pci/hda/patch_hdmi.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sound/pci/hda/patch_hdmi.c b/sound/pci/hda/patch_hdmi.c
index 415701bd10ac8..e7c2f3167f311 100644
--- a/sound/pci/hda/patch_hdmi.c
+++ b/sound/pci/hda/patch_hdmi.c
@@ -1535,7 +1535,7 @@ static void update_eld(struct hda_codec *codec,
 		}
 	}
 
-	if (!eld->eld_valid || eld->eld_size <= 0) {
+	if (!eld->eld_valid || eld->eld_size <= 0 || eld->info.sad_count <= 0) {
 		eld->eld_valid = false;
 		eld->eld_size = 0;
 	}
-- 
2.32.0