Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Fri, 1 Dec 2000 10:15:01 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 1 Dec 2000 10:14:51 -0500 Received: from windsormachine.com ([206.48.122.28]:14866 "EHLO router.windsormachine.com") by vger.kernel.org with ESMTP id ; Fri, 1 Dec 2000 10:14:35 -0500 Message-ID: <3A27B931.DEADF643@windsormachine.com> Date: Fri, 01 Dec 2000 09:44:01 -0500 From: Mike Dresser Organization: Windsor Machine & Stamping X-Mailer: Mozilla 4.75 [en] (Win98; U) X-Accept-Language: en MIME-Version: 1.0 To: Guennadi Liakhovetski CC: linux-kernel@vger.kernel.org Subject: Re: DMA for triton again... In-Reply-To: Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Guennadi Liakhovetski wrote: > Hi > > will try tonight... and will let you know tomorrow... > ... Nop, it didn't work. Mike and everybody having experience / knowledge of Western Digital Caviar AC21600H... If you compare WD's documents at: > http://www.westerndigital.com/service/FAQ/dtr.html > and > http://www.westerndigital.com/products/non-current/drives/ac21600.html > they, respectively ,say: > > UDMA if CCC is A8-AG (AH is not UDMA), D5-D7, Bx, or Cx All others -- PIO Mode 4 > > and > > 16.6 MB/s (burst Mode 4 PIO) * > 16.6 MB/s (burst Mode 2 DMA) ** > 33.3 MB/s (Mode 2 Ultra DMA) *** > > *Max PIO burst rate is specified at 16.6 MB/s using the IORDY signal. > **Max DMA and multi-word DMA burst rate is specified using the DMARQ and DMACK signals. > ***Mode 2 Ultra DMA is supported in the following firmware revisions (CCC Codes: A8, AA, AC, AD, AG, D5, D6, D7, Bx, Cx). > > Which one is true? Do non-UDMA AC21600H (I've got CCC F6) support DMA? > > Is it possible to find out where hdparm -d1 is stopped? Maybe by compiling it with -g and debugging... As far as I understand, BIOS is not an issue, since ide.txt says, that Linux doesn't use BIOS when working with hard drives... > > Thanks > Guennadi > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > Please read the FAQ at http://www.tux.org/lkml/ Well, per my other email, i found a case where the bios DID matter. Yes, the AC21600H supports DMA. Even my dinosaur 850 meg in that same box, works in dma mode, and does get a little bit faster. They're so slow in the first place that it doesn't make much transfer rate difference, but the cpu load goes way down. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/