Re: [PATCH v1] dmaengine: idma64: Use actual device for DMA transfers
From: Vinod Koul <vkoul@kernel.org>
Date: 2019-03-21 14:19:02
Also in:
dmaengine, linux-serial, linux-spi, lkml
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 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel