On 05.12.2016 20:39, Thierry Reding wrote: > On Thu, Nov 10, 2016 at 08:23:39PM +0200, Mikko Perttunen wrote: >> On 64-bit Tegras, buffer object memory allocation may >> return memory above 4G that units behind Host1x cannot >> access. Add the GFP_DMA flag to these allocation when >> IOMMU is not enabled to ensure units can always access >> BO memory. > > I don't think that's entirely true. The display controller can address > more than 32 bits. It's perhaps slightly different from other units that > are behind host1x, but maybe we need a special case here to allow frame- > buffers to reside in higher memory?
I checked and looks like all (or at least most) units can actually address 34 bits /almost always/. The thing that tripped me up was that apparently the firmware for VIC still needs be in the lower 32 bits. So we should be able to drop this patch. > > Thierry > Thanks, Mikko.