From mboxrd@z Thu Jan 1 00:00:00 1970 From: Robert Hancock Subject: Re: [patch 3/3] ata: SWNCQ should be enabled by default Date: Mon, 31 Mar 2008 21:24:12 -0600 Message-ID: <47F1AADC.1080104@shaw.ca> References: <200803282133.m2SLXlWk011463@imap1.linux-foundation.org> <47EE465E.80401@gmail.com> <47EE88C9.3020805@dunaweb.hu> <47EEDACA.4060400@gmail.com> <15F501D1A78BD343BE8F4D8DB854566B1BFE2AF1@hkemmail01.nvidia.com> <47F069D7.3010702@gmail.com> <47F1A888.3020706@shaw.ca> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from idcmail-mo1so.shaw.ca ([24.71.223.10]:30336 "EHLO pd2mo1so.prod.shaw.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752056AbYDAD0U (ORCPT ); Mon, 31 Mar 2008 23:26:20 -0400 Received: from pd3mr5so.prod.shaw.ca (pd3mr5so-qfe3.prod.shaw.ca [10.0.141.12]) by l-daemon (Sun ONE Messaging Server 6.0 HotFix 1.01 (built Mar 15 2004)) with ESMTP id <0JYM00CA3MVW4690@l-daemon> for linux-ide@vger.kernel.org; Mon, 31 Mar 2008 21:26:20 -0600 (MDT) Received: from pn2ml3so.prod.shaw.ca ([10.0.121.147]) by pd3mr5so.prod.shaw.ca (Sun Java System Messaging Server 6.2-7.05 (built Sep 5 2006)) with ESMTP id <0JYM00HT8MVVZG10@pd3mr5so.prod.shaw.ca> for linux-ide@vger.kernel.org; Mon, 31 Mar 2008 21:26:20 -0600 (MDT) Received: from [192.168.1.113] ([70.64.130.4]) by l-daemon (Sun Java System Messaging Server 6.2-7.05 (built Sep 5 2006)) with ESMTP id <0JYM00369MVTKG20@l-daemon> for linux-ide@vger.kernel.org; Mon, 31 Mar 2008 21:26:19 -0600 (MDT) In-reply-to: <47F1A888.3020706@shaw.ca> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Robert Hancock Cc: Tejun Heo , Kuan Luo , Zoltan Boszormenyi , akpm@linux-foundation.org, jeff@garzik.org, linux-ide@vger.kernel.org, Peer Chen , Allen Martin Robert Hancock wrote: > Tejun Heo wrote: >> Kuan Luo wrote: >>> For ADMA, I lean to disable it for default because stability is more >>> important to our customers. At least, bug in this link: >>> http://www.gossamer-threads.com/lists/linux/kernel/885929 is not >>> resolved. >> >> Robert, what do you think? Should we disable ADMA by default from >> 2.6.26-rcX? >> > > I can't say I'm inherently in favor of it, but if people feel strongly > enough about it I won't yell too loudly. If we do disable it, I would > suggest printing out a message saying it can be enabled when the driver > loads if they didn't switch it on, in case people complain about it as a > regression otherwise. BTW, it would be nice if NVIDIA would put some more resources into debugging these issues so that we didn't have to take such an action. With some of these problems, there are definite limits to what we can do to figure out what's going on without knowing what is happening internally in the controller. By my reckoning the known issues are: -Occasional timeouts when issuing the first command after switching from NCQ to non-NCQ commands (even with the udelay() call in the driver to partially work around this). When this happens, going into register mode during error handling times out. -When handling a failed command (ex: caused by a bad sector), going into register mode times out and retrieving result taskfile from ATA registers can cause a MCE due to a northbridge HyperTransport bus transaction timeout (reported by Kuan, I don't think anyone else has mentioned this one). -Hotplug/hot-unplug fails to work properly, hotplug interrupts not raised (seemingly only on certain boards/configurations as I can't duplicate this problem). http://bugzilla.kernel.org/show_bug.cgi?id=8421