Re: [PATCH v4 18/20] iommu/tegra: gart: Don't detach devices from inactive domains

From: Dmitry Osipenko
Date: Tue Sep 25 2018 - 09:42:09 EST


On 9/25/18 1:04 PM, Thierry Reding wrote:
> On Mon, Sep 24, 2018 at 09:05:48PM +0300, Dmitry Osipenko wrote:
>> On 9/24/18 2:00 PM, Thierry Reding wrote:
>>> On Mon, Sep 24, 2018 at 03:41:51AM +0300, Dmitry Osipenko wrote:
>>>> 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@xxxxxxxxx>
>>>> ---
>>>> 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.
>
> Okay, fine.

Thanks, taking as ACK.