Re: [PATCH v7 1/6] base: power: runtime: Export pm_runtime_get/put_suppliers

[Tomasz Figa]

Hi Vivek,

On Wed, Feb 7, 2018 at 7:31 PM, Vivek Gautam
<vivek.gautam@xxxxxxxxxxxxxx> wrote:
> The device link allows the pm framework to tie the supplier and
> consumer. So, whenever the consumer is powered-on the supplier
> is powered-on first.
>
> There are however cases in which the consumer wants to power-on
> the supplier, but not itself.
> E.g., A Graphics or multimedia driver wants to power-on the SMMU
> to unmap a buffer and finish the TLB operations without powering
> on itself.

This sounds strange to me. If the SMMU is powered down, wouldn't the
TLB lose its contents as well (and so no flushing needed)?

Other than that, what kind of hardware operations would be needed
besides just updating the page tables from the CPU?

Best regards,
Tomasz