From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [PATCH] libata: Add a drivers/ide style DMA disable Date: Thu, 20 Sep 2007 10:18:47 +0900 Message-ID: <46F1CA77.5080102@gmail.com> References: <20070822233710.415faaf0@the-village.bc.nu> <46F145E1.1050107@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from nz-out-0506.google.com ([64.233.162.227]:47642 "EHLO nz-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750758AbXITBSy (ORCPT ); Wed, 19 Sep 2007 21:18:54 -0400 Received: by nz-out-0506.google.com with SMTP id s18so308583nze for ; Wed, 19 Sep 2007 18:18:54 -0700 (PDT) In-Reply-To: <46F145E1.1050107@redhat.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Chuck Ebbert Cc: Alan Cox , akpm@osdl.org, linux-ide@vger.kernel.org, jeff@garzik.org Chuck Ebbert wrote: > On 08/22/2007 06:37 PM, Alan Cox wrote: >> This is useful when debugging, handling problem systems, or for >> distributions just to get the system installed so it can be sorted >> out later. >> >> This is a bit smarter than the old IDE one and lets you do >> >> libata.pata_dma=0 Disable all PATA DMA like old IDE >> libata.pata_dma=1 Disk DMA only >> libata.pata_dma=2 ATAPI DMA only >> libata.pata_dma=4 CF DMA only >> >> (or combinations thereof - 0,1,3 being the useful ones I suspect) >> > > This doesn't help distro installers with modular libata, as there's > no good way to get the parameter to the driver. (libata.pata_dma=0 > just causes "unrecognized parameter" message on boot.) Dunno how all those initrd black magics work but SUSE initrd manages to deliver "module.param" parameters on kernel command line to respective modules in initrd. I don't think it gets to modules which are loaded after root is mounted tho. -- tejun