ALSA: au88x0 - Avoid possible Oops at unbinding

The irq handler must check whether the MPU401 instance is still alive.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/pci/au88x0/au88x0_core.c b/sound/pci/au88x0/au88x0_core.c
index 1181c5e..525f881 100644 (file)
--- a/sound/pci/au88x0/au88x0_core.c
+++ b/sound/pci/au88x0/au88x0_core.c
@@ -2477,7 +2477,7 @@ static irqreturn_t vortex_interrupt(int irq, void *dev_id)
                hwread(vortex->mmio, VORTEX_IRQ_STAT);
                handled = 1;
        }
-       if (source & IRQ_MIDI) {
+       if ((source & IRQ_MIDI) && vortex->rmidi) {
                snd_mpu401_uart_interrupt(vortex->irq,
                                          vortex->rmidi->private_data);
                handled = 1;