From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jani Nikula <jani.nikula@linux.intel.com>
Subject: Re: [PATCH] drm/i915: Add a DRM property "psr"
Date: Wed, 19 Mar 2014 17:32:34 +0200
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To: Daniel Vetter <daniel@ffwll.ch>, Siva Chandra <sivachandra@google.com>
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On Wed, 19 Mar 2014, Daniel Vetter <daniel@ffwll.ch> wrote:
> On Tue, Mar 18, 2014 at 01:53:56PM -0700, Siva Chandra wrote:
>> On Tue, Mar 18, 2014 at 1:06 PM, Jesse Barnes <jbarnes@virtuousgeek.org> wrote:
>> > On Tue, 18 Mar 2014 12:51:07 -0700
>> > Siva Chandra <sivachandra@chromium.org> wrote:
>> >
>> >> This property helps one turn PSR "on" and "off" via xrandr.
>> >> The default value is same as that of the module param i915.enable_psr.
>> >>
>> >> Signed-off-by: Siva Chandra <sivachandra@google.com>
>> >> ---
>> >
>> > So are you using this in Chromium for disabling PSR in cases where it
>> > doesn't work?  Or to optimize power consumption when the kernel driver
>> > gets it wrong?  Or just for debug?
>> 
>> We are testing a few PSR panels; Having a knob to turn PSR on and off
>> would be of great convenience for manual testing and for test scripts.
>
> Is the module param not good enough for that? Iirc we recheck that every
> time ...

The only thing missing is that changing the module parameter does not
actually change the psr state. So you need to change the parameter and
then cause intel_edp_psr_update to happen.

Jani.


> -Daniel
> -- 
> Daniel Vetter
> Software Engineer, Intel Corporation
> +41 (0) 79 365 57 48 - http://blog.ffwll.ch
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-- 
Jani Nikula, Intel Open Source Technology Center