[PATCH] ARM: realview: DT support for the PBA8 and PBX-A9

[Russell King - ARM Linux]

On Sun, Mar 06, 2016 at 12:08:27AM +0700, Linus Walleij wrote:
> On Fri, Feb 26, 2016 at 8:01 PM, Robin Murphy <robin.murphy at arm.com> wrote:
> 
> > As with the Versatile AB I scored from a junk pile, trying to boot a
> > full userspace from SD card makes slow progress through a storm of data
> > transfer errors and eventually dies. USB is similarly flaky, with occasional
> > device resets and command errors, but I don't see that it's this patch's
> > fault
> 
> Neither SD/MMC or USB mass storage boots ever worked on these
> shaky PL180 and ISP1760 drivers. Only NFS boot really works.
> 
> I think PL180 can be made to work if we implement a pure polling mode
> (not IRQ, not DMA) to read it.

Don't even try that.  The DMA is very flakey from board to board, and
what works on one doesn't work on another.

>From what I remember playing with that on Versatile PB926, it was a
complete dead-end.  The only sort-of functional peripheral with DMA
on my boards was PL011, and only for transmit.

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