Re: [PATCH v2 2/2] x86/PCI: sta2x11: use default DMA address translation

From: Christoph Hellwig
Date: Wed Oct 30 2019 - 17:45:51 EST


On Fri, Oct 18, 2019 at 01:00:44PM +0200, Nicolas Saenz Julienne wrote:
> The devices found behind this PCIe chip have unusual DMA mapping
> constraints as there is an AMBA interconnect placed in between them and
> the different PCI endpoints. The offset between physical memory
> addresses and AMBA's view is provided by reading a PCI config register,
> which is saved and used whenever DMA mapping is needed.
>
> It turns out that this DMA setup can be represented by properly setting
> 'dma_pfn_offset', 'dma_bus_mask' and 'dma_mask' during the PCI device
> enable fixup. And ultimately allows us to get rid of this device's
> custom DMA functions.
>
> Aside from the code deletion and DMA setup, sta2x11_pdev_to_mapping() is
> moved to avoid warnings whenever CONFIG_PM is not enabled.

Looks sensible to me:

Reviewed-by: Christoph Hellwig <hch@xxxxxx>

But I can't tested it either, and kinda wonder if this code is actually
still used by anyone..