Code review for Raspberry Pi USB driver

[Pavel Pisa]

Hello Deval Shah and others,

On Friday 24 of June 2016 10:45:34 Deval Shah wrote:
> Hello all,
>
> I have successfully ported the bcm283x_dwcotg driver for the Raspberry Pi.
> Changes are shown in the commit >
> https://github.com/deval-maker/rtems-libbsd/commit/fd650f7ded413a0d891b5395
>abb0c8768d71acc7. I need feedback on the code.
>
> Also am getting error in mailbox functions (failed to set power state,
> err=-2). As far as I know Pavel and Mudit are looking into this problem. I
> can not move to next part before solving this issue. Please let me know how
> can I contribute if the problem is not already solved.

I have pushes workaround patch to mainline to ensure that
your projects are not blocked by mailbox access problem.
So the problem should be solved for you.

I would work on suggestions/proposal of patches to fix cache
manager for mainline but testing and acknowledge would require
help from more people and would take time.

Your peripherals needs probably to access memory through DMA.
If you use DMA then check if ARM CP15 operations are used
directly for data synchronization (they work correctly)
or if you use portable

    rtems_cache_flush_multiple_data_lines(buf, size);
    rtems_cache_invalidate_multiple_data_lines(buf, size);

thelater are not working on RPi for now. But I consider these
after fixing as better choice for long term goal.

Best wishes,

              Pavel