Re: [PATCH V3 00/21] MMCONFIG refactoring and support for ARM64 PCI hostbridge init based on ACPI

[Mark Salter]

On Thu, 2016-01-14 at 13:44 +0000, Graeme Gregory wrote:
> On Wed, Jan 13, 2016 at 02:20:46PM +0100, Tomasz Nowicki wrote:
> > From the functionality point of view this series might be split into the
> > following logic parts:
> > 1. Make MMCONFIG code arch-agnostic which allows all architectures to collect
> > ÂÂÂPCI config regions and used when necessary.
> > 2. Move non-arch specific bits to the core code.
> > 3. Use MMCONFIG code and implement generic ACPI based PCI host controller driver.
> > 4. Enable above driver on ARM64
> > 
> > Patches has been built on top of 4.4 and can be found here:
> > git@xxxxxxxxxx:semihalf-nowicki-tomasz/linux.git (pci-acpi-v3)
> > 
> > NOTE, this patch set depends on Matthew's patches:
> > http://www.spinics.net/lists/linux-pci/msg45950.html
> > https://github.com/Vality/linux/tree/pci-fixes
> > 
> > This has been tested on Cavium ThunderX server and QEMU.
> > Any help in reviewing and testing is very appreciated.
> 
> I have tested this on my AMD Overdrive so
> 
> Tested-by: Graeme Gregory <graeme.gregory@xxxxxxxxxx>
> 
> But to actually get my r8169 network card working I also need the
> following patch.
> 
> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> index 2fbf840..40e24e2 100644
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -1717,7 +1717,7 @@ void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
> ÂÂÂÂÂÂÂÂset_dev_node(&dev->dev, pcibus_to_node(bus));
> ÂÂÂÂÂÂÂÂdev->dev.dma_mask = &dev->dma_mask;
> ÂÂÂÂÂÂÂÂdev->dev.dma_parms = &dev->dma_parms;
> -ÂÂÂÂÂÂÂdev->dev.coherent_dma_mask = 0xffffffffull;
> +ÂÂÂÂÂÂÂdev->dev.coherent_dma_mask = DMA_BIT_MASK(64);
> ÂÂÂÂÂÂÂÂpci_dma_configure(dev);
> 
> ÂÂÂÂÂÂÂÂpci_set_dma_max_seg_size(dev, 65536);
> 
> I suspect we need to set coherent_dma_mask somewhere in the platform but I do
> not know where this should happen. Hopefully an ARM64 expert can help.

I've run into a number of cards which don't work on some arm64 machines where there are
no DMA address below 4G. For the realtek card you can use r8169.use_dac=1 on the cmdline
to get it to work.

> 
> Graeme
>