On 9/24/18 2:00 PM, Thierry Reding wrote:

On Mon, Sep 24, 2018 at 03:41:51AM +0300, Dmitry Osipenko wrote:

quoted

There could be unlimited number of allocated domains, but only one domain
can be active at a time. Hence devices must be detached only from the
active domain.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/iommu/tegra-gart.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

Do we have a mechanism of switching out different domains? I don't think
we do, so I'm wondering if perhaps a better solution to this would be to
just refuse to create more than one domain in the first place. That
would also allow us to get rid of the global variable gart_handle.

That's what was done in v1, Robin Murphy suggested that it will be
better not to restrict allocation of unpopulated domains. It is
mentioned in the changelog, see comment to v2 changes.