[ALSA] hda-intel - Add black/whitelist for position_fix option
Some devices are known to require position_fix=1 or 2 to make the
driver working correctly. Otherwise the sound gets weird effects,
such as stutters.
Now a black/whitelist is introduced to indicate the position_fix
value explicitly for such misbehaving hardwares. As a first example,
Dell D820 is listed there. More will come later likely...
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
index 83d1ba7..b9a8e23 100644
--- a/sound/pci/hda/hda_intel.c
+++ b/sound/pci/hda/hda_intel.c
@@ -1503,6 +1503,31 @@
}
/*
+ * white/black-listing for position_fix
+ */
+static const struct snd_pci_quirk position_fix_list[] __devinitdata = {
+ SND_PCI_QUIRK(0x1028, 0x01cc, "Dell D820", POS_FIX_NONE),
+ {}
+};
+
+static int __devinit check_position_fix(struct azx *chip, int fix)
+{
+ const struct snd_pci_quirk *q;
+
+ if (fix == POS_FIX_AUTO) {
+ q = snd_pci_quirk_lookup(chip->pci, position_fix_list);
+ if (q) {
+ snd_printdd(KERN_INFO
+ "hda_intel: position_fix set to %d "
+ "for device %04x:%04x\n",
+ q->value, q->subvendor, q->subdevice);
+ return q->value;
+ }
+ }
+ return fix;
+}
+
+/*
* constructor
*/
static int __devinit azx_create(struct snd_card *card, struct pci_dev *pci,
@@ -1536,7 +1561,8 @@
chip->driver_type = driver_type;
chip->msi = enable_msi;
- chip->position_fix = position_fix;
+ chip->position_fix = check_position_fix(chip, position_fix);
+
chip->single_cmd = single_cmd;
#if BITS_PER_LONG != 64