[alsa-devel] When I got sound back by "kernel: hda-intel: Invalid position buffer, using LPIB read method instead."(random fallover)

[Takashi Iwai]

At Sun, 15 Mar 2009 08:33:26 +0900,
Emmanuel Chanel wrote:
> 
> When I got sound back by "kernel: hda-intel: Invalid position buffer,
> using LPIB read method instead."(random fallover)
> 
> It doesn't mean succeed. Sometimes sound get back and sometimes not, at random.

First off, it's no fatal error, so no big worry about it.
If it's annoying, just use position_fix=1  for the time being.

Looks like the position buffer read is unstable on ATI hardwares.
Maybe we should use the similar workaround like VIA controller.
A test patch is blow.  Please give it a try and report back.


thanks,

Takashi

---
diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
index 92a73e8..57166fe 100644
--- a/sound/pci/hda/hda_intel.c
+++ b/sound/pci/hda/hda_intel.c
@@ -2059,26 +2059,31 @@ static int __devinit check_position_fix(struct azx *chip, int fix)
 {
 	const struct snd_pci_quirk *q;
 
-	/* Check VIA HD Audio Controller exist */
-	if (chip->pci->vendor == PCI_VENDOR_ID_VIA &&
-	    chip->pci->device == VIA_HDAC_DEVICE_ID) {
+	switch (fix) {
+	case POS_FIX_LPIB:
+	case POS_FIX_POSBUF:
+		return fix;
+	}
+
+	/* Check VIA/ATI HD Audio Controller exist */
+	switch (chip->driver_type) {
+	case AZX_DRIVER_VIA:
+	case AZX_DRIVER_ATI:
 		chip->via_dmapos_patch = 1;
 		/* Use link position directly, avoid any transfer problem. */
 		return POS_FIX_LPIB;
 	}
 	chip->via_dmapos_patch = 0;
 
-	if (fix == POS_FIX_AUTO) {
-		q = snd_pci_quirk_lookup(chip->pci, position_fix_list);
-		if (q) {
-			printk(KERN_INFO
-				    "hda_intel: position_fix set to %d "
-				    "for device %04x:%04x\n",
-				    q->value, q->subvendor, q->subdevice);
-			return q->value;
-		}
+	q = snd_pci_quirk_lookup(chip->pci, position_fix_list);
+	if (q) {
+		printk(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;
+	return POS_FIX_AUTO;
 }
 
 /*