Re: [Linaro-mm-sig] [PATCH 1/2] iommu: call detach also for default_domain before attaching to new one

Hi Marek,

On Wed, Feb 17, 2016 at 03:42:54PM +0100, Marek Szyprowski wrote:

From driver perspective the default_domains don't really differ from the 'other' domains. They are just allocated from the IOMMU core and used by the IOMMU/DMA-mapping glue code. That's what I got from reading the code.

There should be also a way to detach the driver even from the default domain to implement the arch_tear_down_dma_ops function.

The attaching/detaching in the iommu-core only manages software state. The iommu-driver can power-down the iommu device when the default-domain is attached and it does not expect any map/unmap calls.

All it has to make sure is that it wakes up the iommu device again when or before these calls are made again.

Joerg