From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Johnson Subject: Re: Is it possible to issue device reset to PMC PM8388 expander using sg3_utils or smp_utils? Date: Thu, 09 Dec 2010 11:05:22 -0800 Message-ID: <4D012872.2000505@aeoncomputing.com> References: <4D0122BC.8060501@aeoncomputing.com> <1291921192.3002.339.camel@mulgrave.site> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail-ew0-f45.google.com ([209.85.215.45]:62077 "EHLO mail-ew0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754176Ab0LITFb (ORCPT ); Thu, 9 Dec 2010 14:05:31 -0500 Received: by ewy10 with SMTP id 10so2017212ewy.4 for ; Thu, 09 Dec 2010 11:05:30 -0800 (PST) In-Reply-To: <1291921192.3002.339.camel@mulgrave.site> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: linux-scsi@vger.kernel.org On 12/9/10 10:59 AM, James Bottomley wrote: > On Thu, 2010-12-09 at 10:41 -0800, Jeff Johnson wrote: >> Greetings, >> >> Is it possible to issue a low level device reset to a PMC-Sierra PM8388 >> 24x3G SAS expander using either sg3_utils or smp_utils? >> >> I am able to enumerate and read the status of the phys on the PM8388, >> read end device information, etc. I tried sg_reset and it does a bus >> reset but not an expander reset. >> >> Technical documentation on the PM8388 is not readily available so I do >> not know if it has a mode select bit or other special method to get the >> expander to reset itself. >> >> I am looking for an inband method to reset the expander to clear a >> condition where some phys in a wide connection fail to link. A power >> cycle clears the condition and I am looking to mimic a power cycle by >> bouncing the expander at the lowest level possible via the SAS host >> connection. > There's no protocol defined way to reset an expander using SMP > functions, so it's not really possible to do it in-band. It's sort of > like asking if there's an ethernet packet you can send to a switch to > cause it to reset. Now that would be fun.... =) > If the wide port isn't forming, you could try doing a hard reset of all > the phys in the port. I have tried that from the hba side using lsiutil and it did not clear the condition. I will try the expander phys and see if the result is any better. When the wide port fails to form the error I see on the three phys that fail to link (from the PM8388 exp side) is "sspl reg trigger error" --Jeff