[PATCH 2/4] ALSA: hda - Return error when open empty hdmi device

[Wang Xingchao <xingchao.wang@linux.intel.com>]

when user open HDMI device 3/7/8, if it has no physical device
connected, return error.
The bug is from Haswell platform, All pins choose converter 0 by default
in hardware level, maybe only pin 1 had valid monitor connected. if user
play audio on pin 0/2, pin 1 can get audio data too.

Signed-off-by: Wang Xingchao <xingchao.wang@linux.intel.com>
---
 sound/pci/hda/patch_hdmi.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/sound/pci/hda/patch_hdmi.c b/sound/pci/hda/patch_hdmi.c
index 8db5eb6..d766f40 100644
--- a/sound/pci/hda/patch_hdmi.c
+++ b/sound/pci/hda/patch_hdmi.c
@@ -1139,6 +1139,9 @@ static int hdmi_pcm_open(struct hda_pcm_stream *hinfo,
 	per_pin = get_pin(spec, pin_idx);
 	eld = &per_pin->sink_eld;
 
+	if (!eld->monitor_present || !eld->eld_valid)
+		return -EIO;
+
 	if (codec->vendor_id == 0x80862807)
 		hsw_verify_cvt_D0(spec, codec);
 		
-- 
1.8.1.2