Re: [PATCH 09/19] drm/i915: get a runtime PM reference when the panel VDD is on

From: Paulo Zanoni <przanoni@gmail.com>
To: Rodrigo Vivi <rodrigo.vivi@gmail.com>
Cc: Intel Graphics Development <intel-gfx@lists.freedesktop.org>,
	Paulo Zanoni <paulo.r.zanoni@intel.com>
Subject: Re: [PATCH 09/19] drm/i915: get a runtime PM reference when the panel VDD is on
Date: Fri, 6 Dec 2013 20:23:26 -0200	[thread overview]
Message-ID: <CA+gsUGR2jO6prJ7bgRhoBuHD6QrJyka3wzm9t=vc6QZS7L_wpQ@mail.gmail.com> (raw)
In-Reply-To: <CABVU7+ug14Loe4MR_SQtSxymaTKR6N2hK5FDCmX1yfz9Le7fnw@mail.gmail.com>

2013/11/29 Rodrigo Vivi <rodrigo.vivi@gmail.com>:
> On Fri, Nov 29, 2013 at 11:59 AM, Paulo Zanoni <przanoni@gmail.com> wrote:
>> 2013/11/29 Rodrigo Vivi <rodrigo.vivi@gmail.com>:
>>> On Thu, Nov 21, 2013 at 01:47:23PM -0200, Paulo Zanoni wrote:
>>>> From: Paulo Zanoni <paulo.r.zanoni@intel.com>
>>>>
>>>> And put it when it's off. Otherwise, when you run pm_pc8 from
>>>> intel-gpu-tools, and the delayed function that disables VDD runs,
>>>> we'll get some messages saying we're touching registers while the HW
>>>> is suspended.
>>>>
>>>> Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
>>>> ---
>>>>  drivers/gpu/drm/i915/intel_dp.c | 7 +++++++
>>>>  1 file changed, 7 insertions(+)
>>>>
>>>> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
>>>> index 28fc070..9e9e3d6 100644
>>>> --- a/drivers/gpu/drm/i915/intel_dp.c
>>>> +++ b/drivers/gpu/drm/i915/intel_dp.c
>>>> @@ -1092,6 +1092,8 @@ void ironlake_edp_panel_vdd_on(struct intel_dp *intel_dp)
>>>>       if (ironlake_edp_have_panel_vdd(intel_dp))
>>>>               return;
>>>>
>>>> +     intel_runtime_pm_get(dev_priv);
>>>> +
>>>>       DRM_DEBUG_KMS("Turning eDP VDD on\n");
>>>>
>>>>       if (!ironlake_edp_have_panel_power(intel_dp))
>>>> @@ -1141,6 +1143,8 @@ static void ironlake_panel_vdd_off_sync(struct intel_dp *intel_dp)
>>>>               DRM_DEBUG_KMS("PP_STATUS: 0x%08x PP_CONTROL: 0x%08x\n",
>>>>               I915_READ(pp_stat_reg), I915_READ(pp_ctrl_reg));
>>>>               msleep(intel_dp->panel_power_down_delay);
>>>> +
>>>> +             intel_runtime_pm_put(dev_priv);
>>>>       }
>>>>  }
>>>>
>>>> @@ -1248,6 +1252,9 @@ void ironlake_edp_panel_off(struct intel_dp *intel_dp)
>>>>       intel_dp->want_panel_vdd = false;
>>>>
>>>>       ironlake_wait_panel_off(intel_dp);
>>>> +
>>>> +     /* We got a reference when we enabled the VDD. */
>>>> +     intel_runtime_pm_put(dev_priv);
>>>
>>> I was going to say it was missing a get until I read the comment above.
>>> But if it gets on VDD on, why not just let it put back on VDD off instead?
>>
>> That's the goal of my series. See patches 15 and 16.
>
> I saw both and got your point, but even after them get and put doesn't
> look in a symmetric place for me.
>

We have 1 place where we "get" and 2 places where we "put", because we
have 1 place where we enable EDP_FORCE_VDD and two places where we
disable EDP_FORCE_VDD. If you only count the get/put ratio it doesn't
look symmetric, but if you compare it against the EDP_FORCE_VDD bit,
it will look symmetric :)

> wouldn't make sense on this patch remove both of _put here and add one
> in vdd_off?

You mean ironlake_edp_panel_vdd_off? That function doesn't touch EDP_FORCE_VDD.

> Even after your vdd fixes it would be symmetric.

Well, at this point maybe the VDD fixes will be merged first, so I
will have to update this patch on top of that, and maybe it will make
more sense to the reviewers :)

>
>>
>>>
>>>>  }
>>>>
>>>>  void ironlake_edp_backlight_on(struct intel_dp *intel_dp)
>>>> --
>>>> 1.8.3.1
>>>>
>>>> _______________________________________________
>>>> Intel-gfx mailing list
>>>> Intel-gfx@lists.freedesktop.org
>>>> http://lists.freedesktop.org/mailman/listinfo/intel-gfx
>>
>>
>>
>> --
>> Paulo Zanoni
>
>
>
> --
> Rodrigo Vivi
> Blog: http://blog.vivi.eng.br

-- 
Paulo Zanoni