Re: [PATCH] drm/i915: Fix hpd live status bits for g4x

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

On Thu, 11 Feb 2016, Daniel Vetter <daniel@ffwll.ch> wrote:
> On Wed, Feb 10, 2016 at 07:59:05PM +0200, ville.syrjala@linux.intel.com wrote:
>> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
>> 
>> Looks like g4x hpd live status bits actually agree with the spec. At
>> least they do on the machine I have, and apparently on Nick Bowler's
>> g4x as well.
>> 
>> So gm45 may be the only platform where they don't agree. At least
>> that seems to be the case based on the (somewhat incomplete)
>> logs/dumps in [1], and Daniel has also tested this on his gm45
>> sometime in the past.
>> 
>> So let's change the bits to match the spec on g4x. That actually makes
>> the g4x bits identical to vlv/chv so we can just share the code
>> between those platforms, leaving gm45 as the special case.
>> 
>> [1] https://bugzilla.kernel.org/show_bug.cgi?id=52361
>> 
>> Cc: Shashank Sharma <shashank.sharma@intel.com>
>> Cc: Sonika Jindal <sonika.jindal@intel.com>
>> Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
>> Cc: Jani Nikula <jani.nikula@linux.intel.com>
>> Cc: Nick Bowler <nbowler@draconx.ca>
>> References: https://lists.freedesktop.org/archives/dri-devel/2016-February/100382.html
>> Reported-by: Nick Bowler <nbowler@draconx.ca>
>> Cc: stable@vger.kernel.org
>> Fixes: 237ed86c693d ("drm/i915: Check live status before reading edid")
>> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
>
> Yeah I'm hopeful this will work. Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
>
> Since CI is down and this is super restricted impact and fixing a
> regression I'm voting that we'll pick it up right away. Jani, are you ok
> with that?

Ack.

> -Daniel
>
>> ---
>>  drivers/gpu/drm/i915/i915_reg.h | 15 ++++++++-------
>>  drivers/gpu/drm/i915/intel_dp.c | 14 +++++++-------
>>  2 files changed, 15 insertions(+), 14 deletions(-)
>> 
>> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
>> index 188ad5de020f..678faa957e75 100644
>> --- a/drivers/gpu/drm/i915/i915_reg.h
>> +++ b/drivers/gpu/drm/i915/i915_reg.h
>> @@ -3296,19 +3296,20 @@ enum skl_disp_power_wells {
>>  
>>  #define PORT_HOTPLUG_STAT	_MMIO(dev_priv->info.display_mmio_offset + 0x61114)
>>  /*
>> - * HDMI/DP bits are gen4+
>> + * HDMI/DP bits are g4x+
>>   *
>>   * WARNING: Bspec for hpd status bits on gen4 seems to be completely confused.
>>   * Please check the detailed lore in the commit message for for experimental
>>   * evidence.
>>   */
>> -#define   PORTD_HOTPLUG_LIVE_STATUS_G4X		(1 << 29)
>> +/* Bspec says GM45 should match G4X/VLV/CHV, but reality disagrees */
>> +#define   PORTD_HOTPLUG_LIVE_STATUS_GM45	(1 << 29)
>> +#define   PORTC_HOTPLUG_LIVE_STATUS_GM45	(1 << 28)
>> +#define   PORTB_HOTPLUG_LIVE_STATUS_GM45	(1 << 27)
>> +/* G4X/VLV/CHV DP/HDMI bits again match Bspec */
>> +#define   PORTD_HOTPLUG_LIVE_STATUS_G4X		(1 << 27)
>>  #define   PORTC_HOTPLUG_LIVE_STATUS_G4X		(1 << 28)
>> -#define   PORTB_HOTPLUG_LIVE_STATUS_G4X		(1 << 27)
>> -/* VLV DP/HDMI bits again match Bspec */
>> -#define   PORTD_HOTPLUG_LIVE_STATUS_VLV		(1 << 27)
>> -#define   PORTC_HOTPLUG_LIVE_STATUS_VLV		(1 << 28)
>> -#define   PORTB_HOTPLUG_LIVE_STATUS_VLV		(1 << 29)
>> +#define   PORTB_HOTPLUG_LIVE_STATUS_G4X		(1 << 29)
>>  #define   PORTD_HOTPLUG_INT_STATUS		(3 << 21)
>>  #define   PORTD_HOTPLUG_INT_LONG_PULSE		(2 << 21)
>>  #define   PORTD_HOTPLUG_INT_SHORT_PULSE		(1 << 21)
>> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
>> index a073f04a5330..bbe18996efe6 100644
>> --- a/drivers/gpu/drm/i915/intel_dp.c
>> +++ b/drivers/gpu/drm/i915/intel_dp.c
>> @@ -4490,20 +4490,20 @@ static bool g4x_digital_port_connected(struct drm_i915_private *dev_priv,
>>  	return I915_READ(PORT_HOTPLUG_STAT) & bit;
>>  }
>>  
>> -static bool vlv_digital_port_connected(struct drm_i915_private *dev_priv,
>> -				       struct intel_digital_port *port)
>> +static bool gm45_digital_port_connected(struct drm_i915_private *dev_priv,
>> +					struct intel_digital_port *port)
>>  {
>>  	u32 bit;
>>  
>>  	switch (port->port) {
>>  	case PORT_B:
>> -		bit = PORTB_HOTPLUG_LIVE_STATUS_VLV;
>> +		bit = PORTB_HOTPLUG_LIVE_STATUS_GM45;
>>  		break;
>>  	case PORT_C:
>> -		bit = PORTC_HOTPLUG_LIVE_STATUS_VLV;
>> +		bit = PORTC_HOTPLUG_LIVE_STATUS_GM45;
>>  		break;
>>  	case PORT_D:
>> -		bit = PORTD_HOTPLUG_LIVE_STATUS_VLV;
>> +		bit = PORTD_HOTPLUG_LIVE_STATUS_GM45;
>>  		break;
>>  	default:
>>  		MISSING_CASE(port->port);
>> @@ -4555,8 +4555,8 @@ bool intel_digital_port_connected(struct drm_i915_private *dev_priv,
>>  		return cpt_digital_port_connected(dev_priv, port);
>>  	else if (IS_BROXTON(dev_priv))
>>  		return bxt_digital_port_connected(dev_priv, port);
>> -	else if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
>> -		return vlv_digital_port_connected(dev_priv, port);
>> +	else if (IS_GM45(dev_priv))
>> +		return gm45_digital_port_connected(dev_priv, port);
>>  	else
>>  		return g4x_digital_port_connected(dev_priv, port);
>>  }
>> -- 
>> 2.4.10
>> 

-- 
Jani Nikula, Intel Open Source Technology Center