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authorClemens Ladisch <clemens@ladisch.de>2009-08-10 10:06:53 +0200
committerTakashi Iwai <tiwai@suse.de>2009-08-10 13:14:46 +0200
commit6e2efaacb3579fd9643d0dc59963b58b801c03a1 (patch)
tree06174a90b4a70f24ab75e3f049aa33784f95774d /sound
parented680c4ad478d0fee9740f7d029087f181346564 (diff)
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>
Diffstat (limited to 'sound')
-rw-r--r--sound/pci/ymfpci/ymfpci_main.c20
1 files changed, 15 insertions, 5 deletions
diff --git a/sound/pci/ymfpci/ymfpci_main.c b/sound/pci/ymfpci/ymfpci_main.c
index 2f0925236a1..5518371db13 100644
--- a/sound/pci/ymfpci/ymfpci_main.c
+++ b/sound/pci/ymfpci/ymfpci_main.c
@@ -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,