From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Wilcox Subject: Re: SCSI dynamic power management Date: Mon, 19 Nov 2007 12:18:49 -0700 Message-ID: <20071119191849.GF12494@parisc-linux.org> References: <1195491182.3283.17.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from palinux.external.hp.com ([192.25.206.14]:56094 "EHLO mail.parisc-linux.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750840AbXKSTSv (ORCPT ); Mon, 19 Nov 2007 14:18:51 -0500 Content-Disposition: inline In-Reply-To: Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Alan Stern Cc: James Bottomley , "Salyzyn, Mark" , Oliver Neukum , SCSI development list On Mon, Nov 19, 2007 at 02:16:12PM -0500, Alan Stern wrote: > Regarding this thread's original question, the best idea I've come up > with so far is to store an extra flag in the scsi_device structure > indicating that a suspend or resume transition is underway. When the > flag is set, commands with REQ_PREEMPT would be accepted. If the > device is "suspended" and the flag is clear, then commands would be > delayed or killed in the prep function regardless of REQ_PREEMPT. This > scheme could potentially let unwanted commands go through, but I > haven't been able to think of anything more suitable. You could allow only START_STOP and TUR to go through? -- Intel are signing my paycheques ... these opinions are still mine "Bill, look, we understand that you're interested in selling us this operating system, but compare it to ours. We can't possibly take such a retrograde step."