sound: OSS: mpu401, fix deadlock
Jiri Slaby [Mon, 29 Jun 2009 16:03:34 +0000 (18:03 +0200)]
mpu401_chk_version is called with a spin lock already held. Don't take it
again.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/oss/mpu401.c

index 6c0a770..1b2316f 100644 (file)
@@ -926,31 +926,21 @@ static struct midi_operations mpu401_midi_operations[MAX_MIDI_DEV];
 static void mpu401_chk_version(int n, struct mpu_config *devc)
 {
        int tmp;
-       unsigned long flags;
 
        devc->version = devc->revision = 0;
 
-       spin_lock_irqsave(&devc->lock,flags);
-       if ((tmp = mpu_cmd(n, 0xAC, 0)) < 0)
-       {
-               spin_unlock_irqrestore(&devc->lock,flags);
+       tmp = mpu_cmd(n, 0xAC, 0);
+       if (tmp < 0)
                return;
-       }
        if ((tmp & 0xf0) > 0x20)        /* Why it's larger than 2.x ??? */
-       {
-               spin_unlock_irqrestore(&devc->lock,flags);
                return;
-       }
        devc->version = tmp;
 
-       if ((tmp = mpu_cmd(n, 0xAD, 0)) < 0)
-       {
+       if ((tmp = mpu_cmd(n, 0xAD, 0)) < 0) {
                devc->version = 0;
-               spin_unlock_irqrestore(&devc->lock,flags);
                return;
        }
        devc->revision = tmp;
-       spin_unlock_irqrestore(&devc->lock,flags);
 }
 
 int attach_mpu401(struct address_info *hw_config, struct module *owner)