Re: Aic7x_x_x 6.3.4 && Aic79xx 2.0.5 Updates

From: "Justin T. Gibbs" <gibbs@scsiguy.com>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>,
	James Bottomley <James.Bottomley@SteelEye.com>
Cc: SCSI Mailing List <linux-scsi@vger.kernel.org>,
	Linus Torvalds <torvalds@transmeta.com>,
	Marcelo Tosatti <marcelo@conectiva.com.br>,
	Andrew Morton <akpm@osdl.org>
Subject: Re: Aic7x_x_x 6.3.4 && Aic79xx 2.0.5 Updates
Date: Sat, 27 Dec 2003 09:02:12 -0700	[thread overview]
Message-ID: <3334920000.1072540932@aslan.btc.adaptec.com> (raw)
In-Reply-To: <1072538231.5494.12.camel@dhcp23.swansea.linux.org.uk>

> Or install your own EH handler.

This was something I considered, but is sadly not enough.  You need
at least two other changes to make it work:

1) scsi_done needs to complete commands regardless of the timer
   state.  The implied race condition commented about in scsi_done()
   doesn't exist.  The HBA driver knows whether a command is in flight
   or not.  Attempting to abort a command that is not active can just
   return immediately with whatever status is agreed upon for the API.
   Without this change, a driver must reschedule bogus timers to get
   a completion to take effect.

2) The driver's must be notified of timeouts immediately.  Your idea
   of re-vectoring the timeout handler would do this just fine.

--
Justin