[Intel-gfx] [PATCH 1/4] drm/i915/gen9+: Enable hotplug detection early

[Sharma, Shashank]

Regards

Shashank


On 1/27/2017 3:09 PM, Imre Deak wrote:
> For LSPCON resume time initialization we need to sample the
> corresponding pin's HPD level, but this is only available when HPD
> detection is enabled. Currently we enable detection only when enabling
> HPD interrupts which is too late, so bring the enabling of detection
> earlier.
>
> This is needed by the next patch.
>
> 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>
> Cc: <stable at vger.kernel.org> # v4.9+
> Signed-off-by: Imre Deak <imre.deak at intel.com>
> ---
>   drivers/gpu/drm/i915/i915_irq.c | 71 +++++++++++++++++++++++++++++------------
>   1 file changed, 51 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
> index 8440d8b..6daf522 100644
> --- a/drivers/gpu/drm/i915/i915_irq.c
> +++ b/drivers/gpu/drm/i915/i915_irq.c
> @@ -3142,24 +3142,33 @@ static void ibx_hpd_irq_setup(struct drm_i915_private *dev_priv)
>   	I915_WRITE(PCH_PORT_HOTPLUG, hotplug);
>   }
>   
> +static void spt_hpd_detection_setup(struct drm_i915_private *dev_priv)
> +{
> +	u32 hotplug;
> +
> +	/* Enable digital hotplug on the PCH */
> +	hotplug = I915_READ(PCH_PORT_HOTPLUG);
> +	hotplug |= PORTA_HOTPLUG_ENABLE |
> +		   PORTB_HOTPLUG_ENABLE |
> +		   PORTC_HOTPLUG_ENABLE |
> +		   PORTD_HOTPLUG_ENABLE;
> +	I915_WRITE(PCH_PORT_HOTPLUG, hotplug);
> +
> +	hotplug = I915_READ(PCH_PORT_HOTPLUG2);
> +	hotplug |= PORTE_HOTPLUG_ENABLE;
> +	I915_WRITE(PCH_PORT_HOTPLUG2, hotplug);
> +}
> +
>   static void spt_hpd_irq_setup(struct drm_i915_private *dev_priv)
>   {
> -	u32 hotplug_irqs, hotplug, enabled_irqs;
> +	u32 hotplug_irqs, enabled_irqs;
>   
>   	hotplug_irqs = SDE_HOTPLUG_MASK_SPT;
>   	enabled_irqs = intel_hpd_enabled_irqs(dev_priv, hpd_spt);
>   
>   	ibx_display_interrupt_update(dev_priv, hotplug_irqs, enabled_irqs);
>   
> -	/* Enable digital hotplug on the PCH */
> -	hotplug = I915_READ(PCH_PORT_HOTPLUG);
> -	hotplug |= PORTD_HOTPLUG_ENABLE | PORTC_HOTPLUG_ENABLE |
> -		PORTB_HOTPLUG_ENABLE | PORTA_HOTPLUG_ENABLE;
> -	I915_WRITE(PCH_PORT_HOTPLUG, hotplug);
> -
> -	hotplug = I915_READ(PCH_PORT_HOTPLUG2);
> -	hotplug |= PORTE_HOTPLUG_ENABLE;
> -	I915_WRITE(PCH_PORT_HOTPLUG2, hotplug);
> +	spt_hpd_detection_setup(dev_priv);
>   }
>   
>   static void ilk_hpd_irq_setup(struct drm_i915_private *dev_priv)
> @@ -3196,18 +3205,15 @@ static void ilk_hpd_irq_setup(struct drm_i915_private *dev_priv)
>   	ibx_hpd_irq_setup(dev_priv);
>   }
>   
> -static void bxt_hpd_irq_setup(struct drm_i915_private *dev_priv)
> +static void __bxt_hpd_detection_setup(struct drm_i915_private *dev_priv,
> +					     u32 enabled_irqs)
>   {
> -	u32 hotplug_irqs, hotplug, enabled_irqs;
> -
> -	enabled_irqs = intel_hpd_enabled_irqs(dev_priv, hpd_bxt);
> -	hotplug_irqs = BXT_DE_PORT_HOTPLUG_MASK;
> -
> -	bdw_update_port_irq(dev_priv, hotplug_irqs, enabled_irqs);
> +	u32 hotplug;
>   
>   	hotplug = I915_READ(PCH_PORT_HOTPLUG);
> -	hotplug |= PORTC_HOTPLUG_ENABLE | PORTB_HOTPLUG_ENABLE |
> -		PORTA_HOTPLUG_ENABLE;
> +	hotplug |= PORTA_HOTPLUG_ENABLE |
> +		   PORTB_HOTPLUG_ENABLE |
> +		   PORTC_HOTPLUG_ENABLE;
>   
>   	DRM_DEBUG_KMS("Invert bit setting: hp_ctl:%x hp_port:%x\n",
>   		      hotplug, enabled_irqs);
> @@ -3217,7 +3223,6 @@ static void bxt_hpd_irq_setup(struct drm_i915_private *dev_priv)
>   	 * For BXT invert bit has to be set based on AOB design
>   	 * for HPD detection logic, update it based on VBT fields.
>   	 */
> -
>   	if ((enabled_irqs & BXT_DE_PORT_HP_DDIA) &&
>   	    intel_bios_is_port_hpd_inverted(dev_priv, PORT_A))
>   		hotplug |= BXT_DDIA_HPD_INVERT;
> @@ -3231,6 +3236,23 @@ static void bxt_hpd_irq_setup(struct drm_i915_private *dev_priv)
>   	I915_WRITE(PCH_PORT_HOTPLUG, hotplug);
>   }
>   
> +static void bxt_hpd_detection_setup(struct drm_i915_private *dev_priv)
> +{
> +	__bxt_hpd_detection_setup(dev_priv, BXT_DE_PORT_HOTPLUG_MASK);
Do we need another layer of internal function ? Why cant the content of 
__bxt_hpd_detection_setup be here, just
like spd_hpd_detection_setup, as they both are static to the file ?
> +}
> +
> +static void bxt_hpd_irq_setup(struct drm_i915_private *dev_priv)
> +{
> +	u32 hotplug_irqs, enabled_irqs;
> +
> +	enabled_irqs = intel_hpd_enabled_irqs(dev_priv, hpd_bxt);
> +	hotplug_irqs = BXT_DE_PORT_HOTPLUG_MASK;
> +
> +	bdw_update_port_irq(dev_priv, hotplug_irqs, enabled_irqs);
> +
> +	__bxt_hpd_detection_setup(dev_priv, enabled_irqs);
> +}
> +
>   static void ibx_irq_postinstall(struct drm_device *dev)
>   {
>   	struct drm_i915_private *dev_priv = to_i915(dev);
> @@ -3246,6 +3268,12 @@ static void ibx_irq_postinstall(struct drm_device *dev)
>   
>   	gen5_assert_iir_is_zero(dev_priv, SDEIIR);
>   	I915_WRITE(SDEIMR, ~mask);
> +
> +	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 */
> +	else
> +		spt_hpd_detection_setup(dev_priv);
>   }
>   
>   static void gen5_gt_irq_postinstall(struct drm_device *dev)
> @@ -3457,6 +3485,9 @@ static void gen8_de_irq_postinstall(struct drm_i915_private *dev_priv)
>   
>   	GEN5_IRQ_INIT(GEN8_DE_PORT_, ~de_port_masked, de_port_enables);
>   	GEN5_IRQ_INIT(GEN8_DE_MISC_, ~de_misc_masked, de_misc_masked);
> +
> +	if (IS_GEN9_LP(dev_priv))
I have not done the delta analysis between hotplug interrupts, but this 
will be true for GLK too.
Should we bother ?

- Shashank
> +		bxt_hpd_detection_setup(dev_priv);
>   }
>   
>   static int gen8_irq_postinstall(struct drm_device *dev)