Re: [PATCH v6 7/7] iommu/exynos: Use device dependency links to control runtime pm

On Thu, Nov 10, 2016 at 12:31 AM, Luis R. Rodriguez [off-list ref] wrote:

On Tue, Nov 08, 2016 at 02:29:24PM +0100, Marek Szyprowski wrote:

quoted

This patch uses recently introduced device dependency links to track the
runtime pm state of the master's device. The goal is to let SYSMMU
controller device's runtime PM to follow the runtime PM state of the
respective master's device. This way each SYSMMU controller is active
only when its master's device is active and can properly restore or save
its state instead on runtime PM transition of master's device.
This approach replaces old behavior, when SYSMMU controller was set to
runtime active once after attaching to the master device. In the new
approach SYSMMU controllers no longer prevents respective power domains
to be turned off when master's device is not being used.

The dependency links also enforces proper order of suspending/restoring
devices during system sleep transition, so there is no more need to use
LATE_SYSTEM_SLEEP_PM_OPS-based workaround for ensuring that SYSMMUs are
suspended after their master devices.

Patches 1-6 seems reasonable to me, however in so far as this patch is
concerned I'd appreaciate if you and Rafael can reply to Lukas Wunner's
questions.

Which questions exactly do you mean?

Thanks,
Rafael