[alsa-devel] [PATCH AUTOSEL 5.4 366/459] ALSA: hda/hdmi - add retry logic to parse_intel_hdmi()

[Sasha Levin]

From: Kai Vehmanen <kai.vehmanen at linux.intel.com>

[ Upstream commit 2928fa0a97ebb9549cb877fdc99aed9b95438c3a ]

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 at linux.intel.com>
Reviewed-by: Takashi Iwai <tiwai at suse.de>
Link: https://lore.kernel.org/r/20200120160117.29130-4-kai.vehmanen@linux.intel.com
Signed-off-by: Takashi Iwai <tiwai at suse.de>
Signed-off-by: Sasha Levin <sashal at kernel.org>
---
 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 8ac805a634f4e..307ca1f036762 100644
--- a/sound/pci/hda/patch_hdmi.c
+++ b/sound/pci/hda/patch_hdmi.c
@@ -2794,9 +2794,12 @@ 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;
-- 
2.20.1