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Date: Wed, 22 Jun 2016 12:30:00 -0400 (EDT)
From: Alan Stern <stern@rowland.harvard.edu>
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To: Joseph Salisbury <joseph.salisbury@canonical.com>
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Subject: Re: [v4.2-rc1 Regression] usb: Enable LPM for USB 2.01+ full-speed
 devices
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On Wed, 22 Jun 2016, Joseph Salisbury wrote:

> Hi Rupesh,
> 
> A kernel bug report was opened against Ubuntu [0].  After a kernel
> bisect, it was found that reverting the following commit resolved this bug:
> 
> commit a8425292816ceaa8c49e29d2114e85d85a73e080
> Author: Rupesh Tatiya <rtatiya@codeaurora.org>
> Date:   Tue Apr 14 16:36:55 2015 +0530
> 
>     usb: Enable LPM for USB 2.01+ full-speed devices
> 
> 
> The regression was introduced as of v4.2-rc1.
> 
> I was hoping to get your feedback, since you are the patch author.  Do
> you think gathering any additional data will help diagnose this issue,
> or would it be best to submit a revert request?

Another option is to add a NO_LPM quirks entry for the troublesome 
device.

Alan Stern