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| author | Takashi Iwai <tiwai@suse.de> | 2006-06-27 18:28:53 +0200 |
|---|---|---|
| committer | Jaroslav Kysela <perex@suse.cz> | 2006-09-23 10:37:08 +0200 |
| commit | 6dbe662874ba08585eaf732d126762c25ac8e3f7 (patch) | |
| tree | 7460c36d4d848f223b682f7a700866bcf6dbc7d5 /sound/pci/intel8x0.c | |
| parent | 2b29b13c5794f648cd5e839796496704d787f5a6 (diff) | |
| download | lwn-6dbe662874ba08585eaf732d126762c25ac8e3f7.tar.gz lwn-6dbe662874ba08585eaf732d126762c25ac8e3f7.zip | |
[ALSA] Add experimental support of aggressive AC97 power-saving mode
Added CONFIG_SND_AC97_POWER_SAVE kernel config to enable the support
of aggressive AC97 power-saving mode. In this mode, the AC97
powerdown register bits are dynamically controlled at each open/close
of PCM streams.
The mode is activated via power_save option for snd-ac97-codec
driver. As default it's off. It can be turned on/off on the fly
via sysfs, too.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
Diffstat (limited to 'sound/pci/intel8x0.c')
| -rw-r--r-- | sound/pci/intel8x0.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/sound/pci/intel8x0.c b/sound/pci/intel8x0.c index 6874263f1681..72dbaedcbdf5 100644 --- a/sound/pci/intel8x0.c +++ b/sound/pci/intel8x0.c @@ -2251,6 +2251,16 @@ static int snd_intel8x0_ich_chip_init(struct intel8x0 *chip, int probing) /* ACLink on, 2 channels */ cnt = igetdword(chip, ICHREG(GLOB_CNT)); cnt &= ~(ICH_ACLINK | ICH_PCM_246_MASK); +#ifdef CONFIG_SND_AC97_POWER_SAVE + /* do cold reset - the full ac97 powerdown may leave the controller + * in a warm state but actually it cannot communicate with the codec. + */ + iputdword(chip, ICHREG(GLOB_CNT), cnt & ~ICH_AC97COLD); + cnt = igetdword(chip, ICHREG(GLOB_CNT)); + udelay(10); + iputdword(chip, ICHREG(GLOB_CNT), cnt | ICH_AC97COLD); + msleep(1); +#else /* finish cold or do warm reset */ cnt |= (cnt & ICH_AC97COLD) == 0 ? ICH_AC97COLD : ICH_AC97WARM; iputdword(chip, ICHREG(GLOB_CNT), cnt); @@ -2265,6 +2275,7 @@ static int snd_intel8x0_ich_chip_init(struct intel8x0 *chip, int probing) return -EIO; __ok: +#endif if (probing) { /* wait for any codec ready status. * Once it becomes ready it should remain ready @@ -2485,7 +2496,7 @@ static int intel8x0_resume(struct pci_dev *pci) card->shortname, chip); chip->irq = pci->irq; synchronize_irq(chip->irq); - snd_intel8x0_chip_init(chip, 1); + snd_intel8x0_chip_init(chip, 0); /* re-initialize mixer stuff */ if (chip->device_type == DEVICE_INTEL_ICH4) { @@ -2615,6 +2626,7 @@ static void __devinit intel8x0_measure_ac97_clock(struct intel8x0 *chip) /* not 48000Hz, tuning the clock.. */ chip->ac97_bus->clock = (chip->ac97_bus->clock * 48000) / pos; printk(KERN_INFO "intel8x0: clocking to %d\n", chip->ac97_bus->clock); + snd_ac97_update_power(chip->ac97[0], AC97_PCM_FRONT_DAC_RATE, 0); } #ifdef CONFIG_PROC_FS |