[U-Boot] [PATCH] net: fec: Avoid MX28 bus sync issue

Troy Kisky
2013-07-15T21:18:24Z

On 7/15/2013 1:20 PM, Albert ARIBAUD wrote:
> Hi Troy,
>
> On Mon, 15 Jul 2013 10:39:54 -0700, Troy Kisky
> <troy.kisky@boundarydevices.com> wrote:
>
>>> Besides, Marek and I had in fact investigated barriers, adding some as
>>> I did in times past in mvgbe.c, and fiddling with the one already in
>>> dcache_flush_range(). None of this had any effect.
>> You tried adding a dsb() to dcache_flush_range()?
>> That should have fixed the problem as well.
> There already was a memory barrier -- the only one kind known bu
> ARM926J-S, which is a write buffer(s) drain -- and no, it should not
> have fixed the problem (and did not), because the issue is not about
> pushing the transactions out of the CPU soon enough; it is about having
> the EMI perform them before it passes our 'go' command to the ENET DMA.
>
Thanks for straightening me out. My back just popped a couple of times.

Troy