From mboxrd@z Thu Jan 1 00:00:00 1970 From: Brad Campbell Subject: Re: Machine hanging on synchronize cache on shutdown 2.6.22-rc4-git[45678] Date: Mon, 18 Jun 2007 15:40:55 +0400 Message-ID: <46766F47.1080405@wasp.net.au> References: <200706181129.l5IBT0Sa002063@harpo.it.uu.se> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <200706181129.l5IBT0Sa002063@harpo.it.uu.se> Sender: linux-raid-owner@vger.kernel.org To: Mikael Pettersson Cc: htejun@gmail.com, linux-ide@vger.kernel.org, linux-raid@vger.kernel.org List-Id: linux-raid.ids Mikael Pettersson wrote: >>> I don't think sata_promise is the guilty party here. Looks like some >>> layer above sata_promise got confused about the state of the interface. >> But locking up hard after hardreset is a problem of sata_promise, no? > > Maybe, maybe not. The original report doesn't specify where/how > the machine hung. It hangs in the process of trying to power it off. Unmount everything and halt the machine. I've tried halt with and without the -h. With the -h you can hear the drives spin down, then it tries to spin them up again and hangs. Without the -h it just hangs hard where you see in the photo. > Brad: can you enable sysrq and check if the kernel responds to > sysrq when it appears to hang, and if so, where it's executing? All my kernels have sysrq enabled. Once the hard reset is displayed on the screen everything locks. > sata_promise just passes sata_std_hardreset to ata_do_eh. > I've certainly seen EH hardresets work before, so I'm assuming > that something in this particular situation (PHY offlined, > kernel close to shutting down) breaks things. That is my thought. I thought on a .22-rc kernel if I used halt -h and it spun the disks down that the kernel would detect that and not try to flush the caches on them, or have I read something incorrectly? > FWIW, I'm seeing scsi layer accesses (cache flushes) after things > like rmmod sata_promise. They error out and don't seem to cause > any harm, but the fact that they occur at all makes me nervous. Brad -- "Human beings, who are almost unique in having the ability to learn from the experience of others, are also remarkable for their apparent disinclination to do so." -- Douglas Adams