ALSA: hda - Enable sync_write and reset for Conexant codecs

This is an attempt to fix S3-resume problems reported for a few
laptops with different Conexant codecs.  They show the communication
stalls at some time in S3, and the driver falls back into the
single-cmd mode.  This leads to the silent output or the lack of
auto-mute feature.

As a workaround, here enables the sync_write and the bus-reset flags
to make the communication more stable.

Bugzilla: https://bugzilla.novell.com/show_bug.cgi?id=740115
Bugzilla: https://bugzilla.novell.com/show_bug.cgi?id=738397

Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 12 insertions, 0 deletions

diff --git a/sound/pci/hda/patch_conexant.c b/sound/pci/hda/patch_conexant.c
index a7a5733aa4d2..117ae4c22be0 100644
--- a/sound/pci/hda/patch_conexant.c
+++ b/sound/pci/hda/patch_conexant.c
@@ -4414,6 +4414,18 @@ static int patch_conexant_auto(struct hda_codec *codec)
         codec->patch_ops = cx_auto_patch_ops;
         if (spec->beep_amp)
                 snd_hda_attach_beep_device(codec, spec->beep_amp);
+
+        /* Some laptops with Conexant chips show stalls in S3 resume,
+         * which falls into the single-cmd mode.
+         * Better to make reset, then.
+         */
+        if (!codec->bus->sync_write) {
+                snd_printd("hda_codec: "
+                           "Enable sync_write for stable communication\n");
+                codec->bus->sync_write = 1;
+                codec->bus->allow_bus_reset = 1;
+        }
+
         return 0;
 }