Return-path: Received: from mfe1.polimi.it ([131.175.12.23]:43923 "EHLO polimi.it" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750886AbXKGRfD (ORCPT ); Wed, 7 Nov 2007 12:35:03 -0500 Date: Wed, 7 Nov 2007 18:33:37 +0100 From: Stefano Brivio To: "John W. Linville" Cc: linux-wireless@vger.kernel.org, bcm43xx-dev@lists.berlios.de Subject: [PATCH] b43legacy: fix shared IRQ race condition Message-ID: <20071107183337.4a77dbd4@morte> (sfid-20071107_173508_247738_9B313847) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-wireless-owner@vger.kernel.org List-ID: 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 --- --- wireless-2.6/drivers/net/wireless/b43legacy/main.c.orig 2007-11-07 18:27:54.710703615 +0100 +++ wireless-2.6/drivers/net/wireless/b43legacy/main.c 2007-11-07 18:29:37.731201996 +0100 @@ -2682,6 +2682,17 @@ 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); @@ -2692,14 +2703,6 @@ 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"); -- Ciao Stefano