From 440cb58a7aa979fabb02a38e55bfe93adde0f41c Mon Sep 17 00:00:00 2001 From: Stefano Brivio Date: Wed, 7 Nov 2007 18:33:37 +0100 Subject: [PATCH] b43legacy: fix shared IRQ race condition Fix an IRQ race condition in b43legacy. If we call b43legacy_wireless_core_stop(), it will set the status of the device to INITIALIZED and the IRQ handler won't care any longer about IRQs, thus the kernel will disable the IRQ if it's shared (unless we boot it with the 'irqpoll' option). So we must disable IRQs before changing the device status. Signed-off-by: Stefano Brivio Signed-off-by: John W. Linville --- drivers/net/wireless/b43legacy/main.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/drivers/net/wireless/b43legacy/main.c b/drivers/net/wireless/b43legacy/main.c index f0e56dfc9ecf..1ebb787ef9cf 100644 --- a/drivers/net/wireless/b43legacy/main.c +++ b/drivers/net/wireless/b43legacy/main.c @@ -2781,6 +2781,17 @@ static void b43legacy_wireless_core_stop(struct b43legacy_wldev *dev) if (b43legacy_status(dev) < B43legacy_STAT_STARTED) return; + + /* Disable and sync interrupts. We must do this before than + * setting the status to INITIALIZED, as the interrupt handler + * won't care about IRQs then. */ + spin_lock_irqsave(&wl->irq_lock, flags); + dev->irq_savedstate = b43legacy_interrupt_disable(dev, + B43legacy_IRQ_ALL); + b43legacy_read32(dev, B43legacy_MMIO_GEN_IRQ_MASK); /* flush */ + spin_unlock_irqrestore(&wl->irq_lock, flags); + b43legacy_synchronize_irq(dev); + b43legacy_set_status(dev, B43legacy_STAT_INITIALIZED); mutex_unlock(&wl->mutex); @@ -2791,14 +2802,6 @@ static void b43legacy_wireless_core_stop(struct b43legacy_wldev *dev) ieee80211_stop_queues(wl->hw); /* FIXME this could cause a deadlock */ - /* Disable and sync interrupts. */ - spin_lock_irqsave(&wl->irq_lock, flags); - dev->irq_savedstate = b43legacy_interrupt_disable(dev, - B43legacy_IRQ_ALL); - b43legacy_read32(dev, B43legacy_MMIO_GEN_IRQ_MASK); /* flush */ - spin_unlock_irqrestore(&wl->irq_lock, flags); - b43legacy_synchronize_irq(dev); - b43legacy_mac_suspend(dev); free_irq(dev->dev->irq, dev); b43legacydbg(wl, "Wireless interface stopped\n");