From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: [PATCH] spidernet: enable poll() before registering interrupts Date: Thu, 12 Jul 2007 01:19:11 +0200 Message-ID: <200707120119.12589.arnd@arndb.de> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Cc: cbe-oss-dev@ozlabs.org, netdev@vger.kernel.org, Christian Krafft To: Linas Vepstas Return-path: Received: from moutng.kundenserver.de ([212.227.126.179]:63378 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758355AbXGKXV2 (ORCPT ); Wed, 11 Jul 2007 19:21:28 -0400 Content-Disposition: inline Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org We must not call netif_poll_enable after enabling interrupts, because an interrupt might come in and set the __LINK_STATE_RX_SCHED bit before we get to clear that bit again. If that happens, the next call to the ->poll() function will oops. Signed-off-by: Arnd Bergmann --- This was found during testing with the fedora kernel, with all patches from netdev-2.6.git applied. It may not be the right fix, but this is currently the only way I can get that kernel to boot. One part I don't understand at the moment is that Christian Krafft reported the same problem with tg3, but that driver has all interrupts disabled at the device while calling the request_irq() function, which seems to be the best solution for avoiding the bug in the first place. Index: linux-2.6/drivers/net/spider_net.c =================================================================== --- linux-2.6.orig/drivers/net/spider_net.c +++ linux-2.6/drivers/net/spider_net.c @@ -1997,6 +1997,7 @@ spider_net_open(struct net_device *netde /* further enhancement: setup hw vlan, if needed */ result = -EBUSY; + netif_poll_enable(netdev); if (request_irq(netdev->irq, spider_net_interrupt, IRQF_SHARED, netdev->name, netdev)) goto register_int_failed; @@ -2005,11 +2006,11 @@ spider_net_open(struct net_device *netde netif_start_queue(netdev); netif_carrier_on(netdev); - netif_poll_enable(netdev); return 0; register_int_failed: + netif_poll_disable(netdev); spider_net_free_rx_chain_contents(card); alloc_skbs_failed: spider_net_free_chain(card, &card->rx_chain);