Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750973AbVKDXKz (ORCPT ); Fri, 4 Nov 2005 18:10:55 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750975AbVKDXKz (ORCPT ); Fri, 4 Nov 2005 18:10:55 -0500 Received: from caramon.arm.linux.org.uk ([212.18.232.186]:40205 "EHLO caramon.arm.linux.org.uk") by vger.kernel.org with ESMTP id S1750933AbVKDXKy (ORCPT ); Fri, 4 Nov 2005 18:10:54 -0500 Date: Fri, 4 Nov 2005 23:10:48 +0000 From: Russell King To: Alan Cox , Benjamin Herrenschmidt Cc: linux-kernel@vger.kernel.org, bzolnier@gmail.com Subject: Re: Parallel ATA with libata status with the patches I'm working on Message-ID: <20051104231048.GD12026@flint.arm.linux.org.uk> Mail-Followup-To: Alan Cox , Benjamin Herrenschmidt , linux-kernel@vger.kernel.org, bzolnier@gmail.com References: <1131029686.18848.48.camel@localhost.localdomain> <20051103144830.GF28038@flint.arm.linux.org.uk> <58cb370e0511030702hb06a5f3qc2dfe465ee1d784c@mail.gmail.com> <58cb370e0511031329h7532259y6d3624fbf2d93f88@mail.gmail.com> <1131058464.18848.94.camel@localhost.localdomain> <20051104013054.GF3469@ime.usp.br> <1131111667.26925.31.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1131111667.26925.31.camel@localhost.localdomain> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1065 Lines: 23 On Fri, Nov 04, 2005 at 01:41:06PM +0000, Alan Cox wrote: > While writing the new sl82c05 driver I noticed a real nasty lurking in > the old code. According to the errata docs you have to reset the DMA > engine every transfer to work around chip errata. It also says that this > resets any other ATA transfer in progress. > > If both channels are in use there is no locking between the channels to > stop a reset on one channel as DMA begins making a mess of the other > channel. Looks like serialize should be set on the driver ? Possibly, though benh needs to comment. (I think benh has the only hardware which has the possibility of both channels - the NetWinder only has one channel with one disk.) -- Russell King Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/ maintainer of: 2.6 Serial core - 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/