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| author | James Courtier-Dutton <James@superbug.co.uk> | 2005-07-10 12:04:29 +0200 |
|---|---|---|
| committer | Jaroslav Kysela <perex@suse.cz> | 2005-07-28 12:22:27 +0200 |
| commit | c9eab129fcbcef364b34fb3a70cb2531847e1edf (patch) | |
| tree | 3cb907f6c4bb5c712a8350c1cd0803401653f835 /sound | |
| parent | 7c1d549aa9b22365fe5405c372f840cdbc6315f5 (diff) | |
| download | linux-c9eab129fcbcef364b34fb3a70cb2531847e1edf.tar.gz linux-c9eab129fcbcef364b34fb3a70cb2531847e1edf.tar.bz2 linux-c9eab129fcbcef364b34fb3a70cb2531847e1edf.zip | |
[ALSA] ac97: Fix volume control bit size detection for STAC9704.
AC97 Codec
Signed-off-by: James Courtier-Dutton <James@superbug.co.uk>
Diffstat (limited to 'sound')
| -rw-r--r-- | sound/pci/ac97/ac97_codec.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/sound/pci/ac97/ac97_codec.c b/sound/pci/ac97/ac97_codec.c index 94cd989cff20..1f09653dc0f3 100644 --- a/sound/pci/ac97/ac97_codec.c +++ b/sound/pci/ac97/ac97_codec.c @@ -1078,6 +1078,11 @@ static void check_volume_resolution(ac97_t *ac97, int reg, unsigned char *lo_max for (i = 0 ; i < ARRAY_SIZE(cbit); i++) { unsigned short val; snd_ac97_write(ac97, reg, 0x8080 | cbit[i] | (cbit[i] << 8)); + /* Do the read twice due to buffers on some ac97 codecs. + * e.g. The STAC9704 returns exactly what you wrote the the register + * if you read it immediately. This causes the detect routine to fail. + */ + val = snd_ac97_read(ac97, reg); val = snd_ac97_read(ac97, reg); if (! *lo_max && (val & 0x7f) == cbit[i]) *lo_max = max[i]; |