From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH] tc35815: Remove a wrong netif_wake_queue() call which triggers BUG_ON Date: Tue, 23 Feb 2010 01:25:58 -0800 (PST) Message-ID: <20100223.012558.174368647.davem@davemloft.net> References: <1266592438-10772-1-git-send-email-anemo@mba.ocn.ne.jp> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, ralf.roesch@rw-gmbh.de To: anemo@mba.ocn.ne.jp Return-path: Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:56523 "EHLO sunset.davemloft.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752102Ab0BWJZk (ORCPT ); Tue, 23 Feb 2010 04:25:40 -0500 In-Reply-To: <1266592438-10772-1-git-send-email-anemo@mba.ocn.ne.jp> Sender: netdev-owner@vger.kernel.org List-ID: From: Atsushi Nemoto Date: Sat, 20 Feb 2010 00:13:58 +0900 > The netif_wake_queue() is called correctly (i.e. only on !txfull > condition) from txdone routine. So Unconditional call to the > netif_wake_queue() here is wrong. This might cause calling of > start_xmit routine on txfull state and trigger BUG_ON. > > This bug does not happen when NAPI disabled. After txdone there > must be at least one free tx slot. But with NAPI, this is not > true anymore and the BUG_ON can hits on heavy load. > > In this driver NAPI was enabled on 2.6.33-rc1 so this is > regression from 2.6.32 kernel. > > Reported-by: Ralf Roesch > Signed-off-by: Atsushi Nemoto Patch applied, thanks.