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

[Stéphane Marchesin]

On Fri, Aug 18, 2017 at 2:07 AM, Jani Nikula
<jani.nikula at linux.intel.com> wrote:
> 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?
>

I am CCing intel people who were looking into this bug, and who
suggested to disable DMC as a solution. You can probably talk to them
directly :)

Stéphane


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