From 2928fa0a97ebb9549cb877fdc99aed9b95438c3a Mon Sep 17 00:00:00 2001
From: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Date: Mon, 20 Jan 2020 18:01:17 +0200
Subject: [PATCH] ALSA: hda/hdmi - add retry logic to parse_intel_hdmi()
Git-commit: 2928fa0a97ebb9549cb877fdc99aed9b95438c3a
Patch-mainline: v5.6-rc1
References: git-fixes

The initial snd_hda_get_sub_node() can fail on certain
devices (e.g. some Chromebook models using Intel GLK).
The failure rate is very low, but as this is is part of
the probe process, end-user impact is high.

In observed cases, related hardware status registers have
expected values, but the node query still fails. Retrying
the node query does seem to help, so fix the problem by
adding retry logic to the query. This does not impact
non-Intel platforms.

Buglink: https://github.com/thesofproject/linux/issues/1642
Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/r/20200120160117.29130-4-kai.vehmanen@linux.intel.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>

---
 sound/pci/hda/patch_hdmi.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/sound/pci/hda/patch_hdmi.c b/sound/pci/hda/patch_hdmi.c
index ce3c212ee467..48bddc218829 100644
--- a/sound/pci/hda/patch_hdmi.c
+++ b/sound/pci/hda/patch_hdmi.c
@@ -2833,9 +2833,12 @@ static int alloc_intel_hdmi(struct hda_codec *codec)
 /* parse and post-process for Intel codecs */
 static int parse_intel_hdmi(struct hda_codec *codec)
 {
-	int err;
+	int err, retries = 3;
+
+	do {
+		err = hdmi_parse_codec(codec);
+	} while (err < 0 && retries--);
 
-	err = hdmi_parse_codec(codec);
 	if (err < 0) {
 		generic_spec_free(codec);
 		return err;
-- 
2.16.4