From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964825AbWLTCoX (ORCPT ); Tue, 19 Dec 2006 21:44:23 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964826AbWLTCoX (ORCPT ); Tue, 19 Dec 2006 21:44:23 -0500 Received: from nz-out-0506.google.com ([64.233.162.235]:64663 "EHLO nz-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964825AbWLTCoW (ORCPT ); Tue, 19 Dec 2006 21:44:22 -0500 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:user-agent:mime-version:to:cc:subject:references:in-reply-to:x-enigmail-version:content-type:content-transfer-encoding; b=CbJHTm4NNvraA/YP/VA0xk5eAYrsK/crWYOZLOg/E5G6UcYh8Hhej+zPQnl8XUtFTarpHSrDbL1Bi5h+TelQmCG0bZp/EX6E3zLj6MY65qlayfy43T7sAcr8A0ZfNRhfSK6IhTc+UVlMvFXACyyXgjdJ5KfWlEW+1kzPNS2O7l0= Message-ID: <4588A37F.9040102@gmail.com> Date: Wed, 20 Dec 2006 11:44:15 +0900 From: Tejun Heo User-Agent: Icedove 1.5.0.8 (X11/20061129) MIME-Version: 1.0 To: Jeff Garzik CC: Alan , David Shirley , linux-kernel@vger.kernel.org Subject: Re: SATA DMA problem (sata_uli) References: <20061213112004.59cb186c@localhost.localdomain> <45841B20.9030402@pobox.com> <458884B2.9080802@gmail.com> <45888653.6080702@pobox.com> In-Reply-To: <45888653.6080702@pobox.com> X-Enigmail-Version: 0.94.1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Jeff Garzik wrote: > Tejun Heo wrote: >> Jeff Garzik wrote: >>> Alan wrote: >>>>> I tracked it down to one of the drives being forced into PIO4 mode >>>>> rather than UDMA mode; dmesg bits: >>>>> ata4.00: ATA-7, max UDMA/133, 586072368 sectors: LBA48 NCQ (depth >>>>> 0/32) >>>>> ata4.00: ata4: dev 0 multi count 16 >>>>> ata4.00: simplex DMA is claimed by other device, disabling DMA >>>> Your ULi controller is reporting that it supports UDMA upon only one >>>> channel at a time. The kernel is honouring this information. The older >>>> ULi (was ALi) PATA devices report simplex but let you turn it off so >>>> see if the following does the trick. Test carefully as always with >>>> disk driver >>>> changes. >>>> >>>> (Jeff probably best to check the docs before merging this but I believe >>>> it is sane) >>>> >>>> Signed-off-by: Alan Cox >>> My Uli SATA docs do not appear to cover the bmdma registers :( Only the >>> PCI config registers. >>> >>> But regardless, I think the better fix is to never set ATA_HOST_SIMPLEX >>> if ATA_FLAG_NO_LEGACY is set. >>> >>> None of the SATA controllers I've ever encountered has been simplex. >> >> Just another data point. The same problem is reported by bug #7590. >> >> http://bugzilla.kernel.org/show_bug.cgi?id=7590 >> >> Is somebody brewing a patch? > > Not to my knowledge. Did you just volunteer? ;-) > > /me runs... I'm just gonna ack Alan's patch. * ATA_FLAG_NO_LEGACY is not really used widely (and thus LLDs don't set it rigorously). I think it should be removed once we get initialization model right. * I'm really reluctant to add more LLD-specific knowledge into libata core. We're already carrying too much due to the current init model (libata should initialize host according to probe_ent, so many weirdities should be represented in probe_ent in a form libata core understands). * The idea of clearing simplex for unknown controllers scares the hell out of me. where's mummy... So, I'll ask bug reporter of #7590 to test it. -- tejun