Re: [PATCH v1] dmaengine: idma64: Use actual device for DMA transfers
From: Vinod Koul
Date: Thu Mar 21 2019 - 10:19:03 EST
On 18-03-19, 18:39, Andy Shevchenko wrote:
> Intel IOMMU, when enabled, tries to find the domain of the device,
> assuming it's a PCI one, during DMA operations, such as mapping or
> unmapping. Since we are splitting the actual PCI device to couple of
> children via MFD framework (see drivers/mfd/intel-lpss.c for details),
> the DMA device appears to be a platform one, and thus not an actual one
> that performs DMA. In a such situation IOMMU can't find or allocate
> a proper domain for its operations. As a result, all DMA operations are
> failed.
>
> In order to fix this, supply parent of the platform device
> to the DMA engine framework and fix filter functions accordingly.
>
> We may rely on the fact that parent is a real PCI device, because no
> other configuration is present in the wild.
Applied, thanks
--
~Vinod