From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [PATCH 2/3] libata: extend ata_acpi_cbl_80wire() and fix cable detection in pata_via and pata_amd Date: Sat, 03 Nov 2007 10:16:37 +0900 Message-ID: <472BCBF5.9080507@gmail.com> References: <472B402A.4030009@gmail.com> <472B4078.90009@gmail.com> <20071102154215.1a93249c@the-village.bc.nu> <472BA249.6000107@gmail.com> <20071102234545.61353ce1@the-village.bc.nu> <472BC4F3.7060209@gmail.com> <20071103011251.679334a8@the-village.bc.nu> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from wa-out-1112.google.com ([209.85.146.177]:18972 "EHLO wa-out-1112.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755426AbXKCBQp (ORCPT ); Fri, 2 Nov 2007 21:16:45 -0400 Received: by wa-out-1112.google.com with SMTP id v27so1129574wah for ; Fri, 02 Nov 2007 18:16:44 -0700 (PDT) In-Reply-To: <20071103011251.679334a8@the-village.bc.nu> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Alan Cox Cc: Jeff Garzik , IDE/ATA development list Alan Cox wrote: >> 2. UDMA mode is configured but equal to or under UDMA33. Dunno whether >> it's cable or device limit but anyways you better limit it to UDMA33 too. > > If it is under UDMA33 you know it isn't a cable limit > > If it is UDMA 33 and the device top is > UDMA 33 it might be > > This matters as you've got to account for both master and slave, as well > as hotplug in theory. I'm not sure whether that level of sophistication is necessary here. This is more like a transfer rate filter thing rather than actual cable detection. We're basically just trying to follow what BIOS did. Maybe we should return ATA_CBL_PATA_MAYBE_80 unconditionally and implement ata_acpi_more_filter()? -- tejun