[ALSA] ac97 - Add a workaround for broken quirk for VT1617A codec
On boards with VT1617A codec, the sound disappears suddenly.
This looks like a problem with HPE-bit control that is supposed to be
set in patch_vt1617a(). However, on such problematic hardwares, the
bit is actually reset mysteriously.
The patch adds a workaround for the wrong quirk.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/pci/ac97/ac97_patch.c b/sound/pci/ac97/ac97_patch.c
index 39198e5..2da8981 100644
--- a/sound/pci/ac97/ac97_patch.c
+++ b/sound/pci/ac97/ac97_patch.c
@@ -3446,6 +3446,7 @@
int patch_vt1617a(struct snd_ac97 * ac97)
{
int err = 0;
+ int val;
/* we choose to not fail out at this point, but we tell the
caller when we return */
@@ -3456,7 +3457,13 @@
/* bring analog power consumption to normal by turning off the
* headphone amplifier, like WinXP driver for EPIA SP
*/
- snd_ac97_write_cache(ac97, 0x5c, 0x20);
+ /* We need to check the bit before writing it.
+ * On some (many?) hardwares, setting bit actually clears it!
+ */
+ val = snd_ac97_read(ac97, 0x5c);
+ if (!(val & 0x20))
+ snd_ac97_write_cache(ac97, 0x5c, 0x20);
+
ac97->ext_id |= AC97_EI_SPDIF; /* force the detection of spdif */
ac97->rates[AC97_RATES_SPDIF] = SNDRV_PCM_RATE_44100 | SNDRV_PCM_RATE_48000;
ac97->build_ops = &patch_vt1616_ops;