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[ALSA] mpu401: fix recursive locking in timer 

When the output and input ports are used at the same time, the timer can
be interrupted by the hardware interrupt, so we have to disable
interrupts when we take a lock in the timer.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
This commit is contained in:
Clemens Ladisch 2007-11-12 08:47:57 +01:00 committed by Jaroslav Kysela
parent 56c36ca3b2
commit 60fac85fff
1 changed files with 8 additions and 4 deletions
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12
sound/drivers/mpu401/mpu401_uart.c
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@ -97,23 +97,27 @@ static void snd_mpu401_uart_clear_rx(struct snd_mpu401 *mpu)
static void uart_interrupt_tx(struct snd_mpu401 *mpu)
{
unsigned long flags;
if (test_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode) &&
test_bit(MPU401_MODE_BIT_OUTPUT_TRIGGER, &mpu->mode)) {
spin_lock(&mpu->output_lock);
spin_lock_irqsave(&mpu->output_lock, flags);
snd_mpu401_uart_output_write(mpu);
spin_unlock(&mpu->output_lock);
spin_unlock_irqrestore(&mpu->output_lock, flags);
}
}
static void _snd_mpu401_uart_interrupt(struct snd_mpu401 *mpu)
{
unsigned long flags;
if (mpu->info_flags & MPU401_INFO_INPUT) {
spin_lock(&mpu->input_lock);
spin_lock_irqsave(&mpu->input_lock, flags);
if (test_bit(MPU401_MODE_BIT_INPUT, &mpu->mode))
snd_mpu401_uart_input_read(mpu);
else
snd_mpu401_uart_clear_rx(mpu);
spin_unlock(&mpu->input_lock);
spin_unlock_irqrestore(&mpu->input_lock, flags);
}
if (! (mpu->info_flags & MPU401_INFO_TX_IRQ))
/* ok. for better Tx performance try do some output