Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261468AbTIOPYM (ORCPT ); Mon, 15 Sep 2003 11:24:12 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261477AbTIOPYM (ORCPT ); Mon, 15 Sep 2003 11:24:12 -0400 Received: from smtp.terra.es ([213.4.129.129]:54985 "EHLO tfsmtp3.mail.isp") by vger.kernel.org with ESMTP id S261468AbTIOPYI (ORCPT ); Mon, 15 Sep 2003 11:24:08 -0400 From: CASINO_E To: Jens Axboe Cc: linux-kernel@vger.kernel.org Reply-To: casino_e@terra.es Message-ID: Date: Mon, 15 Sep 2003 17:24:05 +0200 X-Mailer: Netscape Webmail MIME-Version: 1.0 Content-Language: es Subject: Re: SII SATA request size limit X-Accept-Language: es Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1718 Lines: 50 Forgive me if I'm saying something stupid but, do you mean a special case for this controller in ide-dma.c:ide_build_dmatable()? In this case, should not segment size and boundary be included in hwif so we can have a generic ide_build_dmatable() without dealing explicitly with special cases? We could initialize to the default for most controllers and set the values for the exceptions inside each particular driver. ----- Mensaje Original ----- De: Jens Axboe Fecha: Lunes, Septiembre 15, 2003 10:47 am Asunto: Re: SII SATA request size limit > On Fri, Sep 12 2003, Eduardo Casino wrote: > > Hi All, > > > > I had a look at the NetBSD pciide.c driver and found this > interesting> bit of code: > > > > /* > > * Rev. <= 0x01 of the 3112 have a bug that can cause data > > * corruption if DMA transfers cross an 8K boundary. This is > > * apparently hard to tickle, but we'll go ahead and play it > > * safe. > > */ > > if (PCI_REVISION(pa->pa_class) <= 0x01) { > > sc->sc_dma_maxsegsz = 8192; > > sc->sc_dma_boundary = 8192; > > } > > > > This is basically the same as setting hwif->rqsize to 15, but > the NetBSD > > You can do much much better than that, it's pretty simply to just > restrict the segment size and boundary if you have a controller with > such a bug. And then you get the benefit of the larger requests too, > it's basically not a performance hit at that point. > > -- > Jens Axboe > > - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/