DWC OTG TX path optimisation for 11-current

[Andreas Schwarz]

On 30.07.15, Hans Petter Selasky wrote:
> On 07/29/15 21:41, Andreas Schwarz wrote:
>> On 29.07.15, Hans Petter Selasky wrote:
>>
>>> On 07/29/15 17:45, John-Mark Gurney wrote:
>>>> Just for your information, when I start buildworld, the system
>>>>> responds very fast (console, ssh). After about one hour, it starts to
>>>>> print the following warnings:
>>>
>>> Did this happen before r285935 aswell or only after this revision?
>>
>> This will happen since ~r283xxx, there are some reports in this ml,
>> have a look at my post from 2015-06-03.
>>
>
> If this is easy to reproduce for you, can you try the SMSC patch I made?

It's not so easy to reproduce, it will occur under high load (and disk IO)
situations, e.g.when building the world (-j4). But not in every case, 
sometimes buildworld complete without a problem.

If the system is in this state, it will react very very slow. System load 
is high (without a causing process) and it will often hang (during shutdown) 
when performing a reboot. 

I'll try your patch.

-asc