From owner-freebsd-current Tue Dec 14 23:11:44 1999 Delivered-To: freebsd-current@freebsd.org Received: from freebsd.dk (freebsd.dk [212.242.42.178]) by hub.freebsd.org (Postfix) with ESMTP id D304215541 for ; Tue, 14 Dec 1999 23:11:39 -0800 (PST) (envelope-from sos@freebsd.dk) Received: (from sos@localhost) by freebsd.dk (8.9.3/8.9.1) id IAA08425; Wed, 15 Dec 1999 08:11:18 +0100 (CET) (envelope-from sos) From: Soren Schmidt Message-Id: <199912150711.IAA08425@freebsd.dk> Subject: Re: Fallback to PIO (was: Errors from the ata disk driver) In-Reply-To: <19991215065232.A456@mojave.worldwide.lemis.com> from Greg Lehey at "Dec 15, 1999 06:52:32 am" To: grog@lemis.com (Greg Lehey) Date: Wed, 15 Dec 1999 08:11:18 +0100 (CET) Cc: joeo@nks.net, freebsd-current@FreeBSD.ORG X-Mailer: ELM [version 2.4ME+ PL54 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG It seems Greg Lehey wrote: > On Monday, 13 December 1999 at 9:03:16 +0100, Soren Schmidt wrote: > > It seems joeo@nks.net wrote: > >> Will the backdown to PIO mode be permanent till the next reboot of the > >> machine, or will the driver be able to attempt to return to DMA mode after > >> a timeout period. I'm only seeing these errors under really heavy disk > >> activity (mutlitple nfs readers and writers plus rsync/mirror jobs to the > >> vinum volume in question). > > > > The fallback is permanent, but it only occurs after 3 retries on the > > failed request. If it fails 3 times in a row, there is something > > really wrong on that channel, ie bad cableing etc etc... > > Wouldn't it be possible to find some way to manually reenable DMA? > Having to reboot seems rather hard. The retry count is pr request, and if the same request fails 3 times in a row, belive me you dont want to run DMA on that drive :) -Søren To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message