Subject: [PATCH 5/5] arm: dts: Convert mvebu device tree files to 64 bits

From: [email-masked] (Arnd Bergmann)
Date: Fri, 22 Mar 2013 06:55:25 +0000

On Thursday 21 March 2013, Lior Amsalem wrote:
> > From: Jason Gunthorpe [mailto:jgunthorpe at obsidianresearch.com]
> > Sent: Thursday, March 21, 2013 11:46 PM
> >
> > On Thu, Mar 21, 2013 at 11:35:21PM +0200, Lior Amsalem wrote:
> > 
> > > >  *) It would require Linux to change the internal registers address
> > > >     (for now the kernel relies on the bootloader). The problem is that
> > > >     we can't do it early enough to preserve the earlyprintk
> > > >     functionality. Maybe you have suggestions on how to achieve that?
> > >
> > > Please note that all registers and IOs are still 32bit, the 40bit
> > > extension is on the CPU to DRAM path (windows) only.
> > 
> > Ah, I did wonder, since Ezequiel's MBUS driver was the same as on prior
> > families. I guess it is also the case that all on board DMA and DMA from PCI-E
> > devices are restricted to the low 32 bits as well?
> 
> Correct, that's why we sets DMABOUNCE config.
> 

IIRC, DMABOUNCE does not work well in a multiplatform configuration. Have you tried
using swiotlb instead?

	Arnd