From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sergei Shtylyov Subject: Re: [PATCH] sata_rcar: clear STOP bit in bmdma_start() method Date: Wed, 22 May 2013 17:12:48 +0400 Message-ID: <519CC450.6030203@cogentembedded.com> References: <201305212307.55385.sergei.shtylyov@cogentembedded.com> <20130521234128.GD6985@mtj.dyndns.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail-lb0-f177.google.com ([209.85.217.177]:53657 "EHLO mail-lb0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754320Ab3EVNMp (ORCPT ); Wed, 22 May 2013 09:12:45 -0400 Received: by mail-lb0-f177.google.com with SMTP id o10so2028338lbi.22 for ; Wed, 22 May 2013 06:12:44 -0700 (PDT) In-Reply-To: <20130521234128.GD6985@mtj.dyndns.org> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Tejun Heo Cc: linux-ide@vger.kernel.org, vladimir.barinov@cogentembedded.com Hello. On 22-05-2013 3:41, Tejun Heo wrote: >> Iff bmdma_setup() has to stop a DMA transfer before starting a new one, then the >> STOP bit in the ATAPI_CONTROL1 register will remain set (it's only cleared when >> setting the START bit to 1) and then bmdma_start() method will set both START >> and STOP bits simultaneously which should abort the transfer being just started. >> Avoid that by explicitly clearing the STOP bit in bmdma_start() method (in this >> case it will be ignored on write). >> Signed-off-by: Sergei Shtylyov > Applied to libata/for-3.10-fixes w/ stable cc'd. Thanks, I forgot about -stable. Anyway, it doesn't seem that serious as bmdma_setup() usually shouldn't abort DMA. > Thanks. WBR, Sergei