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| author | Clemens Ladisch <clemens@ladisch.de> | 2008-08-29 13:08:34 +0200 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2008-08-29 14:15:19 +0200 |
| commit | df91bc23dcb052ff2da71b3482bf3c5fbf4b8a53 (patch) | |
| tree | e74972c0522e55da1b027b60c4894c853a96a5ba /sound | |
| parent | 93a1a5eb70be5cc14990b97ef2460212e32658dc (diff) | |
| download | lwn-df91bc23dcb052ff2da71b3482bf3c5fbf4b8a53.tar.gz lwn-df91bc23dcb052ff2da71b3482bf3c5fbf4b8a53.zip | |
ALSA: oxygen: fix distorted output on AK4396-based cards
When changing the sample rate, the CMI8788's master clock output becomes
unstable for a short time. The AK4396 needs the master clock to do SPI
writes, so writing to an AK4396 control register directly after a sample
rate change will garble the value. In our case, this leads to the DACs
being misconfigured to I2S sample format, which results in a wrong
output level and horrible distortions on samples louder than -6 dB.
To fix this, we need to wait until the new master clock signal has
become stable before doing SPI writes.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound')
| -rw-r--r-- | sound/pci/oxygen/hifier.c | 4 | ||||
| -rw-r--r-- | sound/pci/oxygen/oxygen.c | 4 |
2 files changed, 8 insertions, 0 deletions
diff --git a/sound/pci/oxygen/hifier.c b/sound/pci/oxygen/hifier.c index 7442460583dd..dad393ae040a 100644 --- a/sound/pci/oxygen/hifier.c +++ b/sound/pci/oxygen/hifier.c @@ -17,6 +17,7 @@ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ +#include <linux/delay.h> #include <linux/pci.h> #include <sound/control.h> #include <sound/core.h> @@ -107,6 +108,9 @@ static void set_ak4396_params(struct oxygen *chip, else value |= AK4396_DFS_QUAD; data->ak4396_ctl2 = value; + + msleep(1); /* wait for the new MCLK to become stable */ + ak4396_write(chip, AK4396_CONTROL_1, AK4396_DIF_24_MSB); ak4396_write(chip, AK4396_CONTROL_2, value); ak4396_write(chip, AK4396_CONTROL_1, AK4396_DIF_24_MSB | AK4396_RSTN); diff --git a/sound/pci/oxygen/oxygen.c b/sound/pci/oxygen/oxygen.c index 7c8ae31eb468..c5829d30ef86 100644 --- a/sound/pci/oxygen/oxygen.c +++ b/sound/pci/oxygen/oxygen.c @@ -28,6 +28,7 @@ * GPIO 1 -> DFS1 of AK5385 */ +#include <linux/delay.h> #include <linux/mutex.h> #include <linux/pci.h> #include <sound/ac97_codec.h> @@ -213,6 +214,9 @@ static void set_ak4396_params(struct oxygen *chip, else value |= AK4396_DFS_QUAD; data->ak4396_ctl2 = value; + + msleep(1); /* wait for the new MCLK to become stable */ + for (i = 0; i < 4; ++i) { ak4396_write(chip, i, AK4396_CONTROL_1, AK4396_DIF_24_MSB); |