Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755151AbaBUTwB (ORCPT ); Fri, 21 Feb 2014 14:52:01 -0500 Received: from www.linutronix.de ([62.245.132.108]:43489 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755083AbaBUTv7 (ORCPT ); Fri, 21 Feb 2014 14:51:59 -0500 Date: Fri, 21 Feb 2014 20:51:59 +0100 (CET) From: Thomas Gleixner To: Alexandre Bounine cc: Andrew Morton , linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, Matt Porter , Xiaotian Feng , Mike Galbraith , stable@vger.kernel.org Subject: Re: [PATCH] rapidio/tsi721: fix tasklet termination in dma channel release In-Reply-To: <1393010358-6837-1-git-send-email-alexandre.bounine@idt.com> Message-ID: References: <1393010358-6837-1-git-send-email-alexandre.bounine@idt.com> User-Agent: Alpine 2.02 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 21 Feb 2014, Alexandre Bounine wrote: > This patch is a modification of the patch originally proposed > by Xiaotian Feng : https://lkml.org/lkml/2012/11/5/413 > This new version disables DMA channel interrupts and ensures that the tasklet > wil not be scheduled again before calling tasklet_kill(). > > Unfortunately the updated patch was not released at that time due to planned > rework of Tsi721 mport driver to use threaded interrupts (which has yet to > happen). > Recently the issue was reported again: https://lkml.org/lkml/2014/2/19/762. > > Description from the original Xiaotian's patch: > > "Some drivers use tasklet_disable in device remove/release process, > tasklet_disable will inc tasklet->count and return. If the tasklet is > not handled yet under some softirq pressure, the tasklet will be > placed on the tasklet_vec, never have a chance to be excuted. This > might lead to a heavy loaded ksoftirqd, wakeup with pending_softirq, > but tasklet is disabled. tasklet_kill should be used in this case." > > This patch is applicable to kernel versions starting from v3.5. > > Signed-off-by: Alexandre Bounine > Cc: Matt Porter > Cc: Xiaotian Feng > Cc: Thomas Gleixner > Cc: Mike Galbraith > Cc: Reviewed-by: Thomas Gleixner -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/