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sound: ymfpci: increase timer resolution to 96 kHz 

Allow the interval timer to be programmed with its full 96 kHz
precision.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Clemens Ladisch 2009-08-10 10:06:53 +02:00 committed by Takashi Iwai
parent ed680c4ad4
commit 6e2efaacb3
2 changed files with 16 additions and 5 deletions
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1
include/sound/ymfpci.h
View File

@ -331,6 +331,7 @@ struct snd_ymfpci {
struct snd_ac97 *ac97;
struct snd_rawmidi *rawmidi;
struct snd_timer *timer;
unsigned int timer_ticks;
struct pci_dev *pci;
struct snd_card *card;

20
sound/pci/ymfpci/ymfpci_main.c
View File

@ -834,7 +834,7 @@ static irqreturn_t snd_ymfpci_interrupt(int irq, void *dev_id)
status = snd_ymfpci_readw(chip, YDSXGR_INTFLAG);
if (status & 1) {
if (chip->timer)
snd_timer_interrupt(chip->timer, chip->timer->sticks);
snd_timer_interrupt(chip->timer, chip->timer_ticks);
}
snd_ymfpci_writew(chip, YDSXGR_INTFLAG, status);
@ -1885,8 +1885,18 @@ static int snd_ymfpci_timer_start(struct snd_timer *timer)
unsigned int count;
chip = snd_timer_chip(timer);
count = (timer->sticks << 1) - 1;
spin_lock_irqsave(&chip->reg_lock, flags);
if (timer->sticks > 1) {
chip->timer_ticks = timer->sticks;
count = timer->sticks - 1;
} else {
/*
* Divisor 1 is not allowed; fake it by using divisor 2 and
* counting two ticks for each interrupt.
*/
chip->timer_ticks = 2;
count = 2 - 1;
}
snd_ymfpci_writew(chip, YDSXGR_TIMERCOUNT, count);
snd_ymfpci_writeb(chip, YDSXGR_TIMERCTRL, 0x03);
spin_unlock_irqrestore(&chip->reg_lock, flags);
@ -1909,14 +1919,14 @@ static int snd_ymfpci_timer_precise_resolution(struct snd_timer *timer,
unsigned long *num, unsigned long *den)
{
*num = 1;
*den = 48000;
*den = 96000;
return 0;
}
static struct snd_timer_hardware snd_ymfpci_timer_hw = {
.flags = SNDRV_TIMER_HW_AUTO,
.resolution = 20833, /* 1/fs = 20.8333...us */
.ticks = 0x8000,
.resolution = 10417, /* 1 / 96 kHz = 10.41666...us */
.ticks = 0x10000,
.start = snd_ymfpci_timer_start,
.stop = snd_ymfpci_timer_stop,
.precise_resolution = snd_ymfpci_timer_precise_resolution,