From mboxrd@z Thu Jan 1 00:00:00 1970 From: Greg KH Subject: Re: [PATCH] hpsa: add heartbeat sysfs host attribute Date: Fri, 12 Aug 2011 19:01:47 -0700 Message-ID: <20110813020147.GB15554@kroah.com> References: <20110812180314.21808.59261.stgit@beardog.cce.hp.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from out2.smtp.messagingengine.com ([66.111.4.26]:53872 "EHLO out2.smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751093Ab1HMCDm (ORCPT ); Fri, 12 Aug 2011 22:03:42 -0400 Content-Disposition: inline In-Reply-To: <20110812180314.21808.59261.stgit@beardog.cce.hp.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: "Stephen M. Cameron" Cc: james.bottomley@hansenpartnership.com, linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, stephenmcameron@gmail.com, thenzl@redhat.com, akpm@linux-foundation.org, mikem@beardog.cce.hp.com On Fri, Aug 12, 2011 at 01:03:14PM -0500, Stephen M. Cameron wrote: > From: Stephen M. Cameron > > The cciss driver had a CCISS_HEARTBEAT ioctl which > was not implemented in hpsa. This ioctl returned a > counter from a register on the Smart Array which the > firmware would periodically update. It can be used > to detect certain kinds of faults (e.g. controller > lockup) by noticing when the value remains constant > for more than a second or two. > > Signed-off-by: Stephen M. Cameron > --- > Documentation/scsi/hpsa.txt | 8 ++++++++ > drivers/scsi/hpsa.c | 18 ++++++++++++++++++ > 2 files changed, 26 insertions(+), 0 deletions(-) > > diff --git a/Documentation/scsi/hpsa.txt b/Documentation/scsi/hpsa.txt > index 891435a..0dac1e0 100644 > --- a/Documentation/scsi/hpsa.txt > +++ b/Documentation/scsi/hpsa.txt > @@ -47,6 +47,7 @@ HPSA specific entries in /sys > /sys/class/scsi_host/host*/firmware_revision > /sys/class/scsi_host/host*/resettable > /sys/class/scsi_host/host*/transport_mode > + /sys/class/scsi_host/host*/heartbeat > > the host "rescan" attribute is a write only attribute. Writing to this > attribute will cause the driver to scan for new, changed, or removed devices > @@ -78,6 +79,13 @@ HPSA specific entries in /sys > kexec tools to warn the user if they attempt to designate a device which is > unable to honor the reset_devices kernel parameter as a dump device. > > + The "heartbeat" read-only attribute returns the value of a heartbeat > + counter register on a Smart Array controller as a 32 bit unsigned > + hexadecimal integer (e.g: "0x12345678"). The value should change > + periodically, not less than once per second. If this value fails to > + change for a period longer than one second, it means something has > + gone wrong (e.g. Smart Array controller firmware has locked up.) > + This all belongs in Documentation/ABI/ care to move it there instead? greg k-h