From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752207AbcDZD3w (ORCPT ); Mon, 25 Apr 2016 23:29:52 -0400 Received: from mga03.intel.com ([134.134.136.65]:12031 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751060AbcDZD3v (ORCPT ); Mon, 25 Apr 2016 23:29:51 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.24,535,1455004800"; d="scan'208";a="940135856" Date: Tue, 26 Apr 2016 09:04:36 +0530 From: Vinod Koul To: Robert Jarzmik Cc: Daniel Mack , Haojian Zhuang , linux-arm-kernel@lists.infradead.org, dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] dmaengine: pxa: handle bus errors Message-ID: <20160426033436.GC2274@localhost> References: <1459200744-13245-1-git-send-email-robert.jarzmik@free.fr> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1459200744-13245-1-git-send-email-robert.jarzmik@free.fr> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Mar 28, 2016 at 11:32:24PM +0200, Robert Jarzmik wrote: > In the current state, upon bus error the driver will spin endlessly, > relaunching the last tx, which will fail again and again : > - a bus error happens > - pxad_chan_handler() is called > - as PXA_DCSR_STOPSTATE is true, the last non-terminated transaction is > lauched, which is the one triggering the bus error, as it didn't > terminate > - moreover, the STOP interrupt fires a new, as the STOPIRQEN is still > active > > Break this logic by stopping the automatic relaunch of a dma channel > upon a bus error, even if there are still pending issued requests on it. > > As dma_cookie_status() seems unable to return DMA_ERROR in its current > form, ie. there seems no way to mark a DMA_ERROR on a per-async-tx > basis, it is chosen in this patch to remember on the channel which > transaction failed, and report it in pxad_tx_status(). > > It's a bit misleading because if T1, T2, T3 and T4 were queued, and T1 > was completed while T2 causes a bus error, the status of T3 and T4 will > be reported as DMA_IN_PROGRESS, while the channel is actually stopped. Applied, thanks -- ~Vinod