Re: [PATCH v2 1/4] dt-bindings: media: venus: Add an optional power domain for perf voting

From: Rob Herring
Date: Fri Jul 17 2020 - 14:56:29 EST


On Thu, Jul 16, 2020 at 11:52 PM Rajendra Nayak <rnayak@xxxxxxxxxxxxxx> wrote:
>
>
> On 7/17/2020 1:29 AM, Rob Herring wrote:
> > On Thu, Jul 16, 2020 at 11:12:16AM +0530, Rajendra Nayak wrote:
> >> Add an optional power domain which when specified can be used for
> >> setting the performance state of Venus.
> >
> > The h/w suddenly grew a new power island/domain? Seems like an abuse of
> > power-domains...
>
> The power-domain always existed, we have just managed to survive without
> having venus support DVFS and have the domain always be at a high performance
> level (set statically by boot code)
> Now, if we care to do DVFS and support better PM on the SoC, its important
> for the devices to manage this additional power domain (and dynamically
> scale it)
>
> That said, if the name 'opp-pd' makes it look like a software construct,
> like Bjorn mentioned, I am fine to give it a real name like 'cx-pd'
> Does that sound good?

He suggested 'cx' as '-pd' would be redundant. I have no idea what
'cx' means, but fine.

> PS: Like I mentioned earlier [1], cx is a shared power island,
> not a power island specific to this block, and definitely not a software
> pm-domain construct.

Put this context/detail into your patches. Assume I don't remember
what happened last week.

Unfortunately, gmail seems to have no way to filter on unread mails in
reply to my replies and doesn't move the thread up in 'Sent' filter,
so older threads get lost.

Rob

> [1] https://lore.kernel.org/patchwork/patch/1241077/