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Message-ID: <20190321141854.GA5348@vkoul-mobl>
Date: Thu, 21 Mar 2019 19:48:54 +0530
From: Vinod Koul <vkoul@...nel.org>
To: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Cc: dmaengine@...r.kernel.org, Daniel Mack <daniel@...que.org>,
Haojian Zhuang <haojian.zhuang@...il.com>,
Robert Jarzmik <robert.jarzmik@...e.fr>,
linux-arm-kernel@...ts.infradead.org,
Mark Brown <broonie@...nel.org>, linux-spi@...r.kernel.org,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
linux-serial@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v1] dmaengine: idma64: Use actual device for DMA transfers
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
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