[Intel-gfx] [PATCH] drm/i915: decouple runtime PM enablement from DMC presence

[Jani Nikula]

On Thu, 17 Aug 2017, Stéphane Marchesin <marcheu at chromium.org> wrote:
> On Mon, Jun 19, 2017 at 11:45 AM, Jani Nikula
> <jani.nikula at linux.intel.com> wrote:
>>
>> On Thu, 15 Jun 2017, Imre Deak <imre.deak at intel.com> wrote:
>> > On Thu, Jun 15, 2017 at 10:20:57AM -0700, Rodrigo Vivi wrote:
>> >> I believe it is worth allowing RPM to work without requiring DMC, no?!
>> >
>> > Not if there is no good reason for not using DMC. It was decided early
>> > on that we won't support that configuration since if you care about the
>> > power saving provided by partially disabling things you probably also
>> > care about the bigger power saving provided by DMC. So that is the
>> > current state of the driver, enabling runtime PM without having DMC
>> > loaded is not supported. Proper support for that would need to be added
>> > after a justification why not to use the firmware.
>>
>> Agreed. We already have too many configurations to support, and we
>> already struggle with our testing coverage as-is. Adding new
>> configurations to be tested is not to be taken lightly.
>>
>
> For context, we are seeing GPU hangs at suspend/resume with DMC
> enabled (feel free to email me if you want to be added to the internal
> bug) which is the reason for this patch. If those GPU hangs can be
> fixed instead, then that would be an even better solution, IMO. Is
> there someone on your side who could help with these hangs?

We need to get the GPU hangs fixed, obviously. Is this reproducible with
upstream code? Do we have a bug about this at bugs.freedesktop.org?
Jani, Jari?

BR,
Jani.


>
> Stéphane
>
>>
>> BR,
>> Jani.
>>
>> --
>> Jani Nikula, Intel Open Source Technology Center

-- 
Jani Nikula, Intel Open Source Technology Center