DWC OTG TX path optimisation for 11-current

[Hans Petter Selasky]

On 08/25/15 21:51, Andreas Schwarz wrote:
> On 24.08.15, Andreas Schwarz wrote:
>
>> With both kernels I was not able to reproduce the initial problem.
>
> By accident, today I run again into the problem (with r287086). 8(
>
> Aug 25 20:27:59 pizelot kernel: smsc0: warning: Failed to write register 0x114
> Aug 25 20:45:32 pizelot kernel: smsc0: warning: Failed to read register 0x114
> Aug 25 20:45:32 pizelot kernel: smsc0: warning: MII is busy
> Aug 25 20:46:08 pizelot kernel: smsc0: warning: Failed to write register 0x114
> Aug 25 20:46:14 pizelot kernel: smsc0: warning: Failed to read register 0x114
> Aug 25 20:46:14 pizelot kernel: smsc0: warning: MII is busy
> Aug 25 20:46:16 pizelot kernel: smsc0: warning: Failed to write register 0x114
> Aug 25 20:46:46 pizelot kernel: smsc0: warning: Failed to read register 0x114
> Aug 25 20:46:46 pizelot kernel: smsc0: warning: MII is busy
> [...]
>

It might seem like some process is using all CPU on core 0, so that USB 
doesn't get a chance to run. I would suggest maybe moving the DWC OTG 
fast IRQ handling to core #1. Is it possible you could enter kgdb, and 
poke around which fast IRQ is doing work there?

--HPS