Re: [PATCH 3/3] drm/i915: cancel the panel VDD work when we do it manually

[Jani Nikula <jani.nikula@linux.intel.com>]

On Thu, 31 Oct 2013, Daniel Vetter <daniel@ffwll.ch> wrote:
> On Wed, Oct 30, 2013 at 07:50:28PM -0200, Paulo Zanoni wrote:
>> From: Paulo Zanoni <paulo.r.zanoni@intel.com>
>> 
>> After I reorganized the panel VDD debug messages I was able to spot we
>> were disabling it one extra time. The problem is that we're missing
>> the call to cancel the delayed work in one of the instances where we
>> manually call ironlake_panel_vdd_off_sync().
>> 
>> Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
>> ---
>>  drivers/gpu/drm/i915/intel_dp.c | 1 +
>>  1 file changed, 1 insertion(+)
>> 
>> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
>> index 8db1fda..f2280b4 100644
>> --- a/drivers/gpu/drm/i915/intel_dp.c
>> +++ b/drivers/gpu/drm/i915/intel_dp.c
>> @@ -1159,6 +1159,7 @@ void ironlake_edp_panel_vdd_off(struct intel_dp *intel_dp, bool sync)
>>  	intel_dp->want_panel_vdd = false;
>>  
>>  	if (sync) {
>> +		cancel_delayed_work_sync(&intel_dp->panel_vdd_work);
>
> This will deadlock since we hold the mode_config.mutex here, and the
> panel_vdd_work also needs that. I've merged the other two patches.

Ooof, reviewer facepalm.

So we are calling ironlake_panel_vdd_off_sync() twice in this path, but
that shouldn't matter, as we have

if (!intel_dp->want_panel_vdd && ironlake_edp_have_panel_vdd(intel_dp))

in there, right? Paulo, is that what you're seeing, or something else?


BR,
Jani.



> -Daniel
>
>>  		ironlake_panel_vdd_off_sync(intel_dp);
>>  	} else {
>>  		/*
>> -- 
>> 1.8.3.1
>> 
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>
> -- 
> 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