[Intel-gfx] [PATCH 4/4] drm/i915/gen5+, pch: Enable hotplug detection early

[Sharma, Shashank]

Reviewed-by: Shashank Sharma <shashank.sharma at intel.com>

Regards
Shashank
On 1/27/2017 3:09 PM, Imre Deak wrote:
> To be consistent with the recent change to enable hotplug detection
> early on GEN9 platforms do the same on all non-GMCH platforms starting
> from GEN5. On GMCH platforms enabling detection without interrupts isn't
> trivial, since AUX and HPD have a shared interrupt line. It could be
> done there too by using a SW interrupt mask, but I punt on that for now.
>
> Cc: Shashank Sharma <shashank.sharma at intel.com>
> Cc: Jani Nikula <jani.nikula at linux.intel.com>
> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
> Signed-off-by: Imre Deak <imre.deak at intel.com>
> ---
>   drivers/gpu/drm/i915/i915_irq.c | 79 ++++++++++++++++++++++++++---------------
>   1 file changed, 50 insertions(+), 29 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
> index 6daf522..88c10b1 100644
> --- a/drivers/gpu/drm/i915/i915_irq.c
> +++ b/drivers/gpu/drm/i915/i915_irq.c
> @@ -3109,9 +3109,34 @@ static u32 intel_hpd_enabled_irqs(struct drm_i915_private *dev_priv,
>   	return enabled_irqs;
>   }
>   
> +static void ibx_hpd_detection_setup(struct drm_i915_private *dev_priv)
> +{
> +	u32 hotplug;
> +
> +	/*
> +	 * Enable digital hotplug on the PCH, and configure the DP short pulse
> +	 * duration to 2ms (which is the minimum in the Display Port spec).
> +	 * The pulse duration bits are reserved on LPT+.
> +	 */
> +	hotplug = I915_READ(PCH_PORT_HOTPLUG);
> +	hotplug &= ~(PORTB_PULSE_DURATION_MASK |
> +		     PORTC_PULSE_DURATION_MASK |
> +		     PORTD_PULSE_DURATION_MASK);
> +	hotplug |= PORTB_HOTPLUG_ENABLE | PORTB_PULSE_DURATION_2ms;
> +	hotplug |= PORTC_HOTPLUG_ENABLE | PORTC_PULSE_DURATION_2ms;
> +	hotplug |= PORTD_HOTPLUG_ENABLE | PORTD_PULSE_DURATION_2ms;
> +	/*
> +	 * When CPU and PCH are on the same package, port A
> +	 * HPD must be enabled in both north and south.
> +	 */
> +	if (HAS_PCH_LPT_LP(dev_priv))
> +		hotplug |= PORTA_HOTPLUG_ENABLE;
> +	I915_WRITE(PCH_PORT_HOTPLUG, hotplug);
> +}
> +
>   static void ibx_hpd_irq_setup(struct drm_i915_private *dev_priv)
>   {
> -	u32 hotplug_irqs, hotplug, enabled_irqs;
> +	u32 hotplug_irqs, enabled_irqs;
>   
>   	if (HAS_PCH_IBX(dev_priv)) {
>   		hotplug_irqs = SDE_HOTPLUG_MASK;
> @@ -3123,23 +3148,7 @@ static void ibx_hpd_irq_setup(struct drm_i915_private *dev_priv)
>   
>   	ibx_display_interrupt_update(dev_priv, hotplug_irqs, enabled_irqs);
>   
> -	/*
> -	 * Enable digital hotplug on the PCH, and configure the DP short pulse
> -	 * duration to 2ms (which is the minimum in the Display Port spec).
> -	 * The pulse duration bits are reserved on LPT+.
> -	 */
> -	hotplug = I915_READ(PCH_PORT_HOTPLUG);
> -	hotplug &= ~(PORTD_PULSE_DURATION_MASK|PORTC_PULSE_DURATION_MASK|PORTB_PULSE_DURATION_MASK);
> -	hotplug |= PORTD_HOTPLUG_ENABLE | PORTD_PULSE_DURATION_2ms;
> -	hotplug |= PORTC_HOTPLUG_ENABLE | PORTC_PULSE_DURATION_2ms;
> -	hotplug |= PORTB_HOTPLUG_ENABLE | PORTB_PULSE_DURATION_2ms;
> -	/*
> -	 * When CPU and PCH are on the same package, port A
> -	 * HPD must be enabled in both north and south.
> -	 */
> -	if (HAS_PCH_LPT_LP(dev_priv))
> -		hotplug |= PORTA_HOTPLUG_ENABLE;
> -	I915_WRITE(PCH_PORT_HOTPLUG, hotplug);
> +	ibx_hpd_detection_setup(dev_priv);
>   }
>   
>   static void spt_hpd_detection_setup(struct drm_i915_private *dev_priv)
> @@ -3171,9 +3180,25 @@ static void spt_hpd_irq_setup(struct drm_i915_private *dev_priv)
>   	spt_hpd_detection_setup(dev_priv);
>   }
>   
> +static void ilk_hpd_detection_setup(struct drm_i915_private *dev_priv)
> +{
> +	u32 hotplug;
> +
> +	/*
> +	 * Enable digital hotplug on the CPU, and configure the DP short pulse
> +	 * duration to 2ms (which is the minimum in the Display Port spec)
> +	 * The pulse duration bits are reserved on HSW+.
> +	 */
> +	hotplug = I915_READ(DIGITAL_PORT_HOTPLUG_CNTRL);
> +	hotplug &= ~DIGITAL_PORTA_PULSE_DURATION_MASK;
> +	hotplug |= DIGITAL_PORTA_HOTPLUG_ENABLE |
> +		   DIGITAL_PORTA_PULSE_DURATION_2ms;
> +	I915_WRITE(DIGITAL_PORT_HOTPLUG_CNTRL, hotplug);
> +}
> +
>   static void ilk_hpd_irq_setup(struct drm_i915_private *dev_priv)
>   {
> -	u32 hotplug_irqs, hotplug, enabled_irqs;
> +	u32 hotplug_irqs, enabled_irqs;
>   
>   	if (INTEL_GEN(dev_priv) >= 8) {
>   		hotplug_irqs = GEN8_PORT_DP_A_HOTPLUG;
> @@ -3192,15 +3217,7 @@ static void ilk_hpd_irq_setup(struct drm_i915_private *dev_priv)
>   		ilk_update_display_irq(dev_priv, hotplug_irqs, enabled_irqs);
>   	}
>   
> -	/*
> -	 * Enable digital hotplug on the CPU, and configure the DP short pulse
> -	 * duration to 2ms (which is the minimum in the Display Port spec)
> -	 * The pulse duration bits are reserved on HSW+.
> -	 */
> -	hotplug = I915_READ(DIGITAL_PORT_HOTPLUG_CNTRL);
> -	hotplug &= ~DIGITAL_PORTA_PULSE_DURATION_MASK;
> -	hotplug |= DIGITAL_PORTA_HOTPLUG_ENABLE | DIGITAL_PORTA_PULSE_DURATION_2ms;
> -	I915_WRITE(DIGITAL_PORT_HOTPLUG_CNTRL, hotplug);
> +	ilk_hpd_detection_setup(dev_priv);
>   
>   	ibx_hpd_irq_setup(dev_priv);
>   }
> @@ -3271,7 +3288,7 @@ static void ibx_irq_postinstall(struct drm_device *dev)
>   
>   	if (HAS_PCH_IBX(dev_priv) || HAS_PCH_CPT(dev_priv) ||
>   	    HAS_PCH_LPT(dev_priv))
> -		; /* TODO: Enable HPD detection on older PCH platforms too */
> +		ibx_hpd_detection_setup(dev_priv);
>   	else
>   		spt_hpd_detection_setup(dev_priv);
>   }
> @@ -3348,6 +3365,8 @@ static int ironlake_irq_postinstall(struct drm_device *dev)
>   
>   	gen5_gt_irq_postinstall(dev);
>   
> +	ilk_hpd_detection_setup(dev_priv);
> +
>   	ibx_irq_postinstall(dev);
>   
>   	if (IS_IRONLAKE_M(dev_priv)) {
> @@ -3488,6 +3507,8 @@ static void gen8_de_irq_postinstall(struct drm_i915_private *dev_priv)
>   
>   	if (IS_GEN9_LP(dev_priv))
>   		bxt_hpd_detection_setup(dev_priv);
> +	else if (IS_BROADWELL(dev_priv))
> +		ilk_hpd_detection_setup(dev_priv);
>   }
>   
>   static int gen8_irq_postinstall(struct drm_device *dev)