From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthias Prager Subject: Re: 'Device not ready' issue on mpt2sas since 3.1.10 Date: Mon, 23 Jul 2012 01:14:00 +0200 Message-ID: <500C8938.2080607@matthiasprager.de> References: <4FFB32E5.1050109@farcaster.org> <4FFB7354.8040809@matthiasprager.de> <4FFB8A86.7000009@farcaster.org> <4FFCBA4C.4000502@farcaster.org> <4FFD6F3D.2030708@matthiasprager.de> <4FFD8410.7050604@matthiasprager.de> <20120717180932.GB2878@google.com> <5005BF7D.2050703@matthiasprager.de> <20120717200136.GC24336@google.com> <500A9D7C.8080801@matthiasprager.de> <20120722173146.GE5144@dhcp-172-17-108-109.mtv.corp.google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from dd15408.kasserver.com ([85.13.136.168]:32976 "EHLO dd15408.kasserver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752409Ab2GVXOG (ORCPT ); Sun, 22 Jul 2012 19:14:06 -0400 In-Reply-To: <20120722173146.GE5144@dhcp-172-17-108-109.mtv.corp.google.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Tejun Heo Cc: Robert Trace , linux-scsi@vger.kernel.org, Jens Axboe , Eric Moore , "James E.J. Bottomley" , Alan , "Darrick J. Wong" , Matthias Prager Hello Tejun, Am 22.07.2012 19:31, schrieb Tejun Heo:> > I haven't consulted SAT but it seems like a bug in SAS driver or > firmware. If it's a driver bug, we better fix it there. If a > firmware bug, working around those is one of major roles of drivers, > so I think setting allow_restart is fine. as it turns out my workaround (setting allow_restart=1) isn't all that useful after all. There are no more i/o errors because the drive just never goes to standby mode anymore (at least 'hdparm -y /dev/sda' does not seem to have any effect anymore). I don't really understand why - do sas drives ever get to standby mode? (they have allow_restart=1 set by default) And is this desired or expected behavior for sata disk on sas controllers? For the moment the only way for me to have my sata drives sleeping without i/o errors is to revert your original commit (85ef06d1d252f6a2e73b678591ab71caad4667bb - tested with kernels 3.1.10, 3.4.4, 3.4.5, 3.4.6 and 3.5.0) -- Matthias P.S. I hope I'm not getting on everybody's nerves here (especially yours Tejun)