On 18/06/14 02:48, Benjamin Herrenschmidt wrote: > On Wed, 2014-06-18 at 11:05 +1000, Dave Airlie wrote: >> >> I don't think we ever ioremap GART, it should kmap GART pages, ioremap >> should only happen for VRAM areas AFAIK, >> >> This isn't some 32-bit vs 36-bit BAR or something, I seem to remember BenH >> mentioning something like that before. > > Yes, it's a recurring problem in the DRM with physical addresses that are > bigger than 32-bit on 32-bit systems. There have been patches done to > fix that but afaik never quite "completed". I can dig internally if > I can put my hand onto something. > > If possible at all, can you try to configure your SoC to bring the MMIO > space of the PCIe within the bottom 32-bit of the chip address space ? >
I've go a hold of a U-Boot build that brings the chip up in 32-bit mode and modified the DTS to suit. Seemed like the easiest way to see whether it would work. It does. I have a Radeon E6460 showing an X display, at the moment using the fbdev driver. Baby steps... > (Or use a 64-bit e5500 based chip ? :-) > Yeah, haven't got any of those lying around ;-) Thanks guys, Martyn -- Martyn Welch (Lead Software Engineer) | Registered in England and Wales GE Intelligent Platforms | (3828642) at 100 Barbirolli Square T +44(0)1327322748 | Manchester, M2 3AB E martyn.welch at ge.com | VAT:GB 927559189
