From mboxrd@z Thu Jan  1 00:00:00 1970
From: Mark Lord <mlord@pobox.com>
Date: Fri, 02 Apr 2010 21:24:07 +0000
Subject: Re: System hangs when using USB 3.0 HD with on Ubuntu
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 <4BB61237.5030000@ru.mvista.com> <4BB61975.1070406@interlog.com>
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To: dgilbert-qazKcTl6WRFWk0Htik3J/w@public.gmane.org
Cc: Sergei Shtylyov <sshtylyov-Igf4POYTYCDQT0dZR+AlfA@public.gmane.org>, Alan Stern <stern-nwvwT67g6+6dFdvTe/nMLpVzexx5G7lz@public.gmane.org>, James Bottomley <James.Bottomley-l3A5Bk7waGM@public.gmane.org>, Jonas Schwertfeger <jschwertfeger-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>, Kay Sievers <kay.sievers-tD+1rO4QERM@public.gmane.org>, David Zeuthen <david-o55+BOBDEFg@public.gmane.org>, linux-hotplug-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Sarah Sharp <sarah.a.sharp-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>, linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, USB Storage List <usb-storage-ijkIwGHArpdIPJnuZ7Njw4oP9KaGy4wf@public.gmane.org>, Matthew Dharm <mdharm-usb-JGfshJpz5UybPZpvUQj5UqxOck334EZe@public.gmane.org>, linux-scsi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Lennart Poettering <lennart-mdGvqq1h2p+GdvJs77BJ7Q@public.gmane.org>

>> Confirming that, what is put in the ATA_16 sector
>> count field is what the ATA command (IDENTIFY DEVICE)
>> expects in its count field. And according to ACS-2 (rev 2)
>> for IDENTIFY DEVICE that is "N/A" which I would
>> interpret as zero.
>
> Ouch. Reviewing that "N/A" in the ATA spec: it means
> that neither the host nor device should check that
> field. So it could be any value, in this case 1.
..

I'll update hdparm (version 9.29) to supply a sector count of "1"
for IDENTIFY commands, just to satisfy the buggy bridge chip.

Cheers
-- 
Mark Lord
Real-Time Remedies Inc.
mlord@pobox.com