From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1423073Ab2JaPAh (ORCPT ); Wed, 31 Oct 2012 11:00:37 -0400 Received: from hqemgate04.nvidia.com ([216.228.121.35]:18423 "EHLO hqemgate04.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1423051Ab2JaPAd (ORCPT ); Wed, 31 Oct 2012 11:00:33 -0400 X-PGP-Universal: processed; by hqnvupgp07.nvidia.com on Wed, 31 Oct 2012 07:47:50 -0700 Message-ID: <50913CAC.5090808@nvidia.com> Date: Wed, 31 Oct 2012 20:28:52 +0530 From: Laxman Dewangan User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.13) Gecko/20101208 Thunderbird/3.1.7 MIME-Version: 1.0 To: Dmitry Osipenko CC: "swarren@wwwdotorg.org" , "vinod.koul@intel.com" , "linux-tegra@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH V2] dma: tegra: avoid channel lock up after free References: <508EA04D.5050805@wwwdotorg.org> <1351552833-4132-1-git-send-email-digetx@gmail.com> In-Reply-To: <1351552833-4132-1-git-send-email-digetx@gmail.com> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tuesday 30 October 2012 04:50 AM, Dmitry Osipenko wrote: > Fixed channel "lock up" after free. > > Lock scenario: Channel 1 was allocated and prepared as slave_sg, used and freed. > Now preparation of cyclic dma on channel 1 will fail with err "DMA configuration > conflict" because tdc->isr_handler still selected to handle_once_dma_done. > > This happens because tegra_dma_abort_all() won't be called on channel freeing > if pending list is empty or channel not busy. We need to clear isr_handler > on channel freeing to avoid locking. Also I added small optimization to prepare > functions, so current channel type checked before making allocations. > > Signed-off-by: Dmitry Osipenko > --- Looks good to me. Acked-by: Laxman Dewangan