DWC OTG TX path optimisation for 11-current

[Andreas Schwarz]

On 31.07.15, Andreas Schwarz wrote:
> 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.

This was fast. Patch (smsc.diff) did not help. I've applied the patch, compiled and 
installed the new kernel and started to build the kernel tool-chain. Just 10 minutes 
ago the problem occur again.

-asc