From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alan Cox Subject: Re: [PATCH 1/1] pata_it821x: fix lost interrupt with atapi devices Date: Tue, 18 Sep 2007 05:07:15 -0400 Message-ID: <20070918090715.GA13425@devserv.devel.redhat.com> References: <200709041607.l84G7KsT032647@norden.math.tntech.edu> <18141.42848.537873.349518@alkaid.it.uu.se> <20070906013929.1621849d@the-village.bc.nu> <46EE09D3.9010201@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mx1.redhat.com ([66.187.233.31]:58679 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750968AbXIRJHx (ORCPT ); Tue, 18 Sep 2007 05:07:53 -0400 Content-Disposition: inline In-Reply-To: <46EE09D3.9010201@gmail.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Tejun Heo Cc: Alan Cox , Mikael Pettersson , Jeff Norden , alan@redhat.com, linux-kernel@vger.kernel.org, Albert CC Lee , IDE/ATA development list On Mon, Sep 17, 2007 at 07:00:03AM +0200, Tejun Heo wrote: > I wonder whether we should be using similar check in generic path too. > We have quite a few cases where MWDMA ATAPI devices choking on commands > with small transfer sizes. I don't think we'll experience significant > performance regression with this applied and even if there is some, it's > far better to have slightly slower working device. > > What do you guys think? I think to start with someone should fix the ATAPI state machine. Stick a BUG() in the driver if dma start is called when the atapi command data size is zero Alan