FSL/NXP P5020: USB problems with the latest Git kernels

[Scott Wood]

On Mon, 2018-08-27 at 20:15 +0200, Christian Zigotzky wrote:
> Hello,
> 
> Our users tested the RC1 of kernel 4.19 on their P5020 boards today.
> Unfortunately the USB bug still exists. With mem values bigger than 4096M,
> the USB mouse and keyboard doesn’t work. With the bootarg mem=4096M, the USB
> devices work without any problems. Please compile the RC1 and test it on
> your P5020 board. There is a problem with the memory management since
> 22/08/18. 

I just tested 4.19-rc1 on a T4240 and got a similar problem with MMC.  MMC and
USB on these chips both have a 32-bit DMA limitation.  I'll look into it.

-Scott