plip: replace spin_lock_irq with spin_lock_irqsave in irq context (cabce28e) · Commits · 戴 / test

Plip uses spin_lock_irq/spin_unlock_irq in its IRQ handler (called from parport IRQ handler), the latter enables interrupts without parport subsystem IRQ handler expecting it. The bug can be seen if you compile kernel with lock dependency checking and use plip --- it produces a warning. This patch changes it to spin_lock_irqsave/spin_lock_irqrestore, so that it doesn't enable interrupts when already disabled. Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

drivers/net/plip.c

+4 −3

Original line number	Diff line number	Diff line
		@@ -903,17 +903,18 @@ plip_interrupt(void *dev_id)
		struct net_local *nl;
		struct plip_local *rcv;
		unsigned char c0;
		unsigned long flags;

		nl = netdev_priv(dev);
		rcv = &nl->rcv_data;

		spin_lock_irq (&nl->lock);
		spin_lock_irqsave (&nl->lock, flags);

		c0 = read_status(dev);
		if ((c0 & 0xf8) != 0xc0) {
		if ((dev->irq != -1) && (net_debug > 1))
		printk(KERN_DEBUG "%s: spurious interrupt\n", dev->name);
		spin_unlock_irq (&nl->lock);
		spin_unlock_irqrestore (&nl->lock, flags);
		return;
		}

		@@ -942,7 +943,7 @@ plip_interrupt(void *dev_id)
		break;
		}

		spin_unlock_irq(&nl->lock);
		spin_unlock_irqrestore(&nl->lock, flags);
		}

		static int

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