[ALSA] hda-intel - Add workarounds for STAC codecs

Some machines with STAC codecs seem to have problems (e.g. no audible
playback) when the delay in codec-read routine is too short.
I still don't figure out which command sequence causes this problem
(due to lack of test hardware), but it's known that increasing the
delay fixes.  So, added a stupid workaround here temporarily...

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>

3 files changed, 21 insertions, 2 deletions

diff --git a/sound/pci/hda/hda_codec.h b/sound/pci/hda/hda_codec.h
index 20be7761562d..719e46f6fb36 100644
--- a/sound/pci/hda/hda_codec.h
+++ b/sound/pci/hda/hda_codec.h
@@ -464,6 +464,9 @@ struct hda_bus {
         struct hda_bus_unsolicited *unsol;
 
         struct snd_info_entry *proc;
+
+        /* misc op flags */
+        unsigned int needs_damn_long_delay :1;
 };
 
 /*
diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
index 5f2c3ca863db..fe07bdff60d0 100644
--- a/sound/pci/hda/hda_intel.c
+++ b/sound/pci/hda/hda_intel.c
@@ -559,8 +559,12 @@ static unsigned int azx_rirb_get_response(struct hda_codec *codec)
                 }
                 if (!chip->rirb.cmds)
                         return chip->rirb.res; /* the last value */
-                udelay(10);
-                cond_resched();
+                if (codec->bus->needs_damn_long_delay)
+                        msleep(2); /* temporary workaround */
+                else {
+                        udelay(10);
+                        cond_resched();
+                }
         } while (time_after_eq(timeout, jiffies));
 
         if (chip->msi) {
diff --git a/sound/pci/hda/patch_sigmatel.c b/sound/pci/hda/patch_sigmatel.c
index 1d643b9771a0..24137bc975c4 100644
--- a/sound/pci/hda/patch_sigmatel.c
+++ b/sound/pci/hda/patch_sigmatel.c
@@ -3472,6 +3472,18 @@ static int patch_stac927x(struct hda_codec *codec)
 
         codec->patch_ops = stac92xx_patch_ops;
 
+        /*
+         * !!FIXME!!
+         * The STAC927x seem to require fairly long delays for certain
+         * command sequences.  With too short delays (even if the answer
+         * is set to RIRB properly), it results in the silence output
+         * on some hardwares like Dell.
+         *
+         * The below flag enables the longer delay (see get_response
+         * in hda_intel.c).
+         */
+        codec->bus->needs_damn_long_delay = 1;
+
         return 0;
 }