From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: error handling - DMA to PIO step down sequence Date: Fri, 22 Sep 2006 01:58:53 +0900 Message-ID: <4512C4CD.80000@gmail.com> References: <4511907F.1010104@emc.com> <4512AB17.7040907@gmail.com> <4512BD19.5010401@emc.com> <1158858264.11109.159.camel@localhost.localdomain> <4512C2C0.9010503@emc.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from nz-out-0102.google.com ([64.233.162.200]:30052 "EHLO nz-out-0102.google.com") by vger.kernel.org with ESMTP id S1751344AbWIUQ7J (ORCPT ); Thu, 21 Sep 2006 12:59:09 -0400 Received: by nz-out-0102.google.com with SMTP id n1so428951nzf for ; Thu, 21 Sep 2006 09:59:09 -0700 (PDT) In-Reply-To: <4512C2C0.9010503@emc.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: ric@emc.com Cc: Alan Cox , linux-ide@vger.kernel.org, Jeff Garzik , Mark Lord Ric Wheeler wrote: > Alan Cox wrote: >> Ar Iau, 2006-09-21 am 12:26 -0400, ysgrifennodd Ric Wheeler: >> >>>>> Would this be a reasonable thing for a config option? Better to add >>>>> yet another blacklist for devices that might have a justified need >>>>> for this derating? >> >> I think so. I've got "Adding a set of flags to blacklist entries" on my >> todo list so that we can indicate and deal with different kinds of >> horkage. > > That could be very useful - flag specific drives to disable NCQ > (regardless of the internal setting for drive queue depth) and so on. Yeap, in general, we need a blacklist. For example, some drives only do NCQ w/ only 16 or so commands or others have completely broken NCQ support. But I don't think the broken read log page 10h needs a blacklist entry. It can be easily handled by good default behavior. -- tejun