From 6e2efaacb3579fd9643d0dc59963b58b801c03a1 Mon Sep 17 00:00:00 2001 From: Clemens Ladisch Date: Mon, 10 Aug 2009 10:06:53 +0200 Subject: 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 Signed-off-by: Takashi Iwai --- sound/pci/ymfpci/ymfpci_main.c | 20 +++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-) (limited to 'sound') 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, -- cgit v1.2.3