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[ALSA] mpu401: fix recursive locking in timer

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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