On Thursday 20 March 2014 16:04:36 Ben Dooks wrote: > On 26/02/14 20:57, Arnd Bergmann wrote: > > On Wednesday 26 February 2014 12:48:17 Bjorn Helgaas wrote: > >> On Mon, Feb 24, 2014 at 4:00 AM, Arnd Bergmann <arnd@xxxxxxxx> wrote: > >>> Hi Magnus, > >>> > >>> I noticed during randconfig testing that you enabled DMABOUNCE for the > >>> pci-rcar-gen2 driver as posted in this patch https://lkml.org/lkml/2014/2/5/30 > >>> > >>> I didn't see the original post unfortunately, but I fear we have to > >>> revert it and come up with a better solution, ... > >> > >> Sounds like I should drop the following patches from my pci/host-rcar > >> branch for now? > >> > >> PCI: rcar: Add DMABOUNCE support > >> PCI: rcar: Enable BOUNCE in case of HIGHMEM > >> PCI: rcar: Make the Kconfig dependencies more generic > > > > Sounds good to me. The last patch is actually fine, but you'll have to > > fix the context to apply it without the other two. > > As a note, if we now boot a Lager with DT on 3.14-rc3 series the USB > controllers no longer work with full 2GiB RAM enabled in the device > tree. Did it work before these patches got applied initially? > Could we work around this by having 1GiB of memory defined in the > 32bit memory and then add the rest of the 3GiB from the >32bit > area via LPAE? Will the kernel ever try to allocate DMA memory from > anything >32bit? You can solve the case for dma_alloc_coherent() this way, or by setting the mask correctly. It won't help you for dma_map_* though, which still requires someone to add support for swiotlb or using an IOMMU if present. Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
