umass: AutoSense failed

[Paul Mather]

On Dec 9, 2010, at 5:11 PM, Jeremy Chadwick wrote:

> On Thu, Dec 09, 2010 at 10:35:56PM +0100, Harald Weis wrote:
>> What could be the reason for the following failure?
>> 
>> ugen2.2: <Sony> at usbus2
>> umass0: <Sony Sony DSC, class 0/0, rev 1.10/4.50, addr 2> on usbus2
>> umass0:  RBC over CBI; quirks = 0x0000
>> umass0:1:0:-1: Attached to scbus1
>> (probe0:umass-sim0:0:0:0): AutoSense failed
>> 
>> This occurs on 4 different boxes, all on 8.1-RELEASE.
>> Never happened on previous releases.
>> The camera works on an Ubuntu system.
> 
> Please try a 8.1-STABLE or 8.2-PRERELEASE snapshot (you can boot the
> livefs CD or USB memstick image to test) and see if things are different
> (improved) there.
> 
> ftp://ftp4.freebsd.org/pub/FreeBSD/snapshots/201011/
> 
> 8.x uses a newer/different USB stack than 7.x.


I get something similar to this happening on 8.2-PRERELEASE.  In my case, it's not during boot probing or device attachment.  Instead, it happens occasionally after boot.  The devices concerned are Maxtor OneTouch external USB hard drives.  Every now and then, I will get something akin to the following crop up in the console log:

(da1:umass-sim1:1:0:0): AutoSense failed

I have three of these Maxtor OneTouch drives attached to the system as part of a ZFS pool.  When I get an "AutoSense failed" message, it is usually accompanied by the ZFS pool being marked as faulted.

The Maxtor OneTouch drives are wont to spin down and go into a deep sleep after a period of inactivity and appear very slow to wake up again when I/O occurs.  I have always assumed that the "AutoSense failed" is associated with this---that there is some kind of timeout in the FreeBSD stack that this device is exceeding.  In fact, sometimes the devices fail to probe properly during boot when they are asleep.

This is what the OneTouch normally probes as:

da0 at umass-sim0 bus 0 scbus0 target 0 lun 0
da0: <Maxtor OneTouch 0121> Fixed Direct Access SCSI-4 device 
da0: 40.000MB/s transfers
da0: 953869MB (1953525168 512 byte sectors: 255H 63S/T 121601C)


Cheers,

Paul.