[ALSA] mpu401: fix recursive locking in timer
authorClemens Ladisch <clemens@ladisch.de>
Mon, 12 Nov 2007 07:47:57 +0000 (08:47 +0100)
committerJaroslav Kysela <perex@perex.cz>
Mon, 19 Nov 2007 17:38:32 +0000 (18:38 +0100)
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>
sound/drivers/mpu401/mpu401_uart.c

index 3306ecd..b57f2d5 100644 (file)
@@ -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