Re: [PATCH] drm/i915: Add a DRM property "psr"

Jani Nikula
2014-03-20T14:50:31Z

On Thu, 20 Mar 2014, Siva Chandra <sivachandra@google.com> wrote:
> On Thu, Mar 20, 2014 at 6:25 AM, Jani Nikula
> <jani.nikula@linux.intel.com> wrote:
>> On Thu, 20 Mar 2014, Siva Chandra <sivachandra@google.com> wrote:
>>> On Thu, Mar 20, 2014 at 3:52 AM, Jani Nikula
>>> <jani.nikula@linux.intel.com> wrote:
>>>> If this is for testing only, and the module parameter does not quite cut
>>>> it, please add it to debugfs. That we can pretty much change at will.
>>>
>>> If I understand correctly, you are suggesting that the on/off knob
>>> live in debugfs. So, should the module param in sysfs mirror this
>>> debugfs knob?
>>
>> I guess the simplest thing to move forward would be something to update
>> psr state after the module parameter has been changed, although it's
>> perhaps a bit clumsy to use.
>
> Couldn't understand. May be an example to illustrate what you are saying?

echo 1 > /sys/module/i915/parameters/enable_psr
echo something > sys/kernel/debug/dri/0/i915_edp_psr_update

where that debugfs file essentially calls intel_edp_psr_update() on
update.

I guess it could be i915_edp_psr_enable and echoing there would modify
the module parameter and call update. With debugfs I'm not so fussy.

Jani.

>
> Thanks,
> Siva Chandra

--
Jani Nikula, Intel Open Source Technology Center