From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andi Kleen Subject: Re: [Bugme-new] [Bug 10915] New: echo min_power > /sys/class/scsi_host/host0/active_mode causes problem Date: Mon, 16 Jun 2008 14:48:20 +0200 Message-ID: <87wskpwnor.fsf@basil.nowhere.org> References: <20080615180146.8abb9450.akpm@linux-foundation.org> <1213581610.3517.44.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from smtp-out04.alice-dsl.net ([88.44.63.6]:25283 "EHLO smtp-out04.alice-dsl.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751104AbYFPMsW (ORCPT ); Mon, 16 Jun 2008 08:48:22 -0400 In-Reply-To: <1213581610.3517.44.camel@localhost.localdomain> (James Bottomley's message of "Sun, 15 Jun 2008 21:00:10 -0500") Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: James Bottomley Cc: Andrew Morton , linux-scsi@vger.kernel.org, bugme-daemon@bugzilla.kernel.org, cijoml@volny.cz James Bottomley writes: > > Um ... actually, maybe not. The active_mode file is read only (it has a > NULL store method). It's designed to show what mode the host is > activated in "initiator", "target" (or both or unknown). If echoing > something to a read only sysfs file with no actual store method is > causing this behaviour, the root cause has to be somewhere in sysfs. > > However, since the file has nothing to do with power saving ... unless > some driver I can't find is trying to duplicate it, so there's no reason > to try to echo "min_power" to it, so some of the details on this report > might bear further investigation ... I remember hitting something like this in the past when write() returned 0. Some versions of echo loop in this case. -Andi