[regression] external HDD in USB3 enclosure cannot be dynamically removed (Re: Linux 3.7.5)

[Jonathan Nieder <jrnieder@gmail.com>]

Hi Holger,

Holger Hoffstaette wrote:
>> On Mon, Jan 28, 2013 at 12:42:16PM +0100, Holger Hoffstaette wrote:

>>> Apologies for being late but I'm afraid I just found at least one
>>> regression in this release.
>>>
>>> I have an external HDD in an USB3 enclosure for the occasional backup. I
>>> turn it on, it gets registered as sdX, I mount it/use it/unmount it and
>>> turn it off, which worked fine with kernels including 3.7.4. With 3.7.5
>
> FWIW it didn't really work with 3.7.4 either - just didn't notice before.
>
>>> the kernel seems no longer notified of the changed device power status;
>>> nothing in dmesg and the device stays in the list of SCSI devices as
>>> e.g. shown by lsscsi. This is repeatable. Turning the device back
>>> on/using it works fine, it's just that I cannot dynamically remove it
>>> any longer.
[...]
> No, current 3.8-rc5 did not work either. I first found 3.7.2 OK and 3.7.3
> bad. Bisecting found:
>
> --snip--
> f7965c0846d74b270e246c1470ca955d5078eb07 is the first bad commit
> commit f7965c0846d74b270e246c1470ca955d5078eb07
> Author: Sarah Sharp <sarah.a.sharp@linux.intel.com>
> Date:   Wed Nov 14 17:58:04 2012 -0800
>
>     USB: Handle warm reset failure on empty port.
>
>     commit 65bdac5effd15d6af619b3b7218627ef4d84ed6a upstream.
[...]
> Reverting this from 3.7.3 all the way to 3.8-rc5 makes USB 3.0
> disconnection/power-off device removal work again. Verified both on the
> bisection box and by now also the original machine.

Thanks for tracking this down.  Forwarding to relevant people.

Hope that helps,
Jonathan