From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [PATCH 3/4] libata: add per-dev pio/mwdma/udma_mask Date: Mon, 13 Mar 2006 18:30:52 +0900 Message-ID: <20060313093052.GB2091@htj.dyndns.org> References: <11421469551000-git-send-email-htejun@gmail.com> <44152D64.6000903@pobox.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from zproxy.gmail.com ([64.233.162.203]:12433 "EHLO zproxy.gmail.com") by vger.kernel.org with ESMTP id S932388AbWCMJa6 (ORCPT ); Mon, 13 Mar 2006 04:30:58 -0500 Received: by zproxy.gmail.com with SMTP id 14so1240740nzn for ; Mon, 13 Mar 2006 01:30:58 -0800 (PST) Content-Disposition: inline In-Reply-To: <44152D64.6000903@pobox.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Jeff Garzik Cc: albertcc@tw.ibm.com, alan@lxorguk.ukuu.org.uk, linux-ide@vger.kernel.org On Mon, Mar 13, 2006 at 03:29:24AM -0500, Jeff Garzik wrote: > Tejun Heo wrote: > >Add per-dev pio/mwdma/udma_mask. All transfer mode limits used to be > >applied to ap->*_mask which unnecessarily restricted other devices > >sharing the port. This change will also benefit later EH speed down > >and hotplug. > > > >Signed-off-by: Tejun Heo > > I don't see much value in the separation. Rather than 3 separate masks, > it seems like this patch would be simplified if you simply added > dev->xfer_mask. > The thing is that ap->*_mask's are separated the same way and all masking constants are defined as such. e.g. ap->udma_mask &= ATA_UDMA5; or ap->udma_mask &= ATA_UDMA_MASK_40C; Making dev->*_mask's the same enables share those constants and code convention. So, things to consider here are... 1. Port xfer masks are defined as three separate masks. 2. All the constants are defined according to that. 3. Three separate masks are easier to deal with for LLDD's. I'm okay either way but using different approach for port and device doesn't sound too hot. -- tejun