Re: [PATCH 2/2] dma: add Qualcomm Technologies HIDMA channel driver

From: Timur Tabi
Date: Fri Oct 30 2015 - 17:55:26 EST


On 10/30/2015 04:42 PM, Sinan Kaya wrote:

if (WARN_ON(!pdev->dev.dma_mask))
return -ENXIO;

The dma mask has to always be set by the platform code before probe()
is called. If it is not set, you are not allowed to perform DMA.

I tested this on an ACPI platform BTW when I was working on the initial
implementation.

PowerPC sets the mask to 32 bits by default:

http://lxr.free-electrons.com/ident?i=arch_setup_pdev_archdata

Should we do something similar in ARM64? Today, we have to manually set the DMA mask in all drivers.

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