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dmaengine: idma64: Use actual device for DMA transfers

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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.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [for tty parts]
Signed-off-by: Vinod Koul <vkoul@kernel.org>
This commit is contained in:
Andy Shevchenko
2019-03-18 18:39:30 +03:00
committed by Vinod Koul
parent 9e98c678c2
commit 5ba846b1ee
4 changed files with 9 additions and 10 deletions
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4
drivers/tty/serial/8250/8250_dw.c
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@@ -365,7 +365,7 @@ static bool dw8250_fallback_dma_filter(struct dma_chan *chan, void *param)
static bool dw8250_idma_filter(struct dma_chan *chan, void *param)
{
return param == chan->device->dev->parent;
return param == chan->device->dev;
}
/*
@@ -434,7 +434,7 @@ static void dw8250_quirks(struct uart_port *p, struct dw8250_data *data)
data->uart_16550_compatible = true;
}
/* Platforms with iDMA */
/* Platforms with iDMA 64-bit */
if (platform_get_resource_byname(to_platform_device(p->dev),
IORESOURCE_MEM, "lpss_priv")) {
data->dma.rx_param = p->dev->parent;