ALSA: hda/hdmi - add retry logic to parse_intel_hdmi()

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>

diff --git a/sound/pci/hda/patch_hdmi.c b/sound/pci/hda/patch_hdmi.c
index ce3c212ee467704fd6ac28b959aae23db59837ab..48bddc218829dded2cd19b91b06b19cdffe3f4e6 100644 (file)
--- 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;