Re: [PATCH] drm/i915: revert intel_dp_probe_oui call during HPD interrupt handler

[Clint Taylor <clinton.a.taylor@intel.com>]

On 06/05/2014 02:26 AM, Daniel Vetter wrote:
> On Wed, Jun 04, 2014 at 03:29:41PM -0700, clinton.a.taylor@intel.com wrote:
>> From: Clint Taylor <clinton.a.taylor@intel.com>
>>
>> Remove OUI read function from the lower half interrupt handler. Upon
>> closing the eDP panel lid an HPD interrupt is generated. The lower half
>> handler calls intel_dp_probe_oui() as part of intel_dp_detect().
>> intel_dp_probe_oui() enables eDP VDD and subsequently disables eDP VDD
>> causing another HPD interrupt. This cycle repeats every 3.6 seconds with
>> VDD asserted for 3.5 of those seconds until the lid is opened again.
>>
>> Revert of 0d198328538276c4459ef5de081e68ae60e6c4c2
>> Revert of 351cfc34db8decb0c5cc1aac7cf1780a0e45c8b1
>>
>> Signed-off-by: Clint Taylor <clinton.a.taylor@intel.com>
>
> Hm, this is funky ... we currently don't handle port A hotplug events, and
> we filter hotplug events properly.
>
This is a Port A panel on ValleyView.


> How does this exactly blow up for you? Or is this port D?
>
[  219.723752] [drm:ironlake_panel_vdd_off_sync], PP_STATUS: 0x00000000 
PP_CONTROL: 0xabcd0000
[  219.823937] [drm:valleyview_irq_handler], hotplug event received, 
stat 0x20100000
[  219.823964] [drm:intel_hpd_irq_handler], Received HPD interrupt on 
PIN 5 - cnt: 0
[  219.824153] [drm:i915_hotplug_work_func], running encoder hotplug 
functions
[  219.824175] [drm:i915_hotplug_work_func], Connector eDP-1 (pin 5) 
received hotplug event.
[  219.824193] [drm:i915_hotplug_work_func], Connector HDMI-A-1 (pin 5) 
received hotplug event.
[  219.824213] [drm:intel_dp_detect], [CONNECTOR:14:eDP-1]
[  219.824229] [drm:ironlake_edp_panel_vdd_on], Turn eDP VDD on

The valleyview_irq_handler() is receiving the HPD event and 
i915_hotplug_work_func() is calling intel_dp_detect().



> We might want to have some filtering here checking whether the edp panel
> is on or off. Also the delayed work is _way_ too long.

We could filter if the lid is closed, but it seemed a lot safer to 
remove the function. Or we could move the Sink and branch OUI reads to 
the training function. If OUI is necessary we should probably also save 
the values to the context.

> -Daniel
>
>> ---
>>   drivers/gpu/drm/i915/intel_dp.c |   23 -----------------------
>>   1 file changed, 23 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
>> index 2a00cb8..246d2c1 100644
>> --- a/drivers/gpu/drm/i915/intel_dp.c
>> +++ b/drivers/gpu/drm/i915/intel_dp.c
>> @@ -2867,27 +2867,6 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp)
>>   	return true;
>>   }
>>
>> -static void
>> -intel_dp_probe_oui(struct intel_dp *intel_dp)
>> -{
>> -	u8 buf[3];
>> -
>> -	if (!(intel_dp->dpcd[DP_DOWN_STREAM_PORT_COUNT] & DP_OUI_SUPPORT))
>> -		return;
>> -
>> -	intel_edp_panel_vdd_on(intel_dp);
>> -
>> -	if (intel_dp_dpcd_read_wake(&intel_dp->aux, DP_SINK_OUI, buf, 3) == 3)
>> -		DRM_DEBUG_KMS("Sink OUI: %02hx%02hx%02hx\n",
>> -			      buf[0], buf[1], buf[2]);
>> -
>> -	if (intel_dp_dpcd_read_wake(&intel_dp->aux, DP_BRANCH_OUI, buf, 3) == 3)
>> -		DRM_DEBUG_KMS("Branch OUI: %02hx%02hx%02hx\n",
>> -			      buf[0], buf[1], buf[2]);
>> -
>> -	edp_panel_vdd_off(intel_dp, false);
>> -}
>> -
>>   int intel_dp_sink_crc(struct intel_dp *intel_dp, u8 *crc)
>>   {
>>   	struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
>> @@ -3178,8 +3157,6 @@ intel_dp_detect(struct drm_connector *connector, bool force)
>>   	if (status != connector_status_connected)
>>   		goto out;
>>
>> -	intel_dp_probe_oui(intel_dp);
>> -
>>   	if (intel_dp->force_audio != HDMI_AUDIO_AUTO) {
>>   		intel_dp->has_audio = (intel_dp->force_audio == HDMI_AUDIO_ON);
>>   	} else {
>> --
>> 1.7.9.5
>>
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>