[Intel-gfx] [PATCH 2/2] drm/i915: Set invert bit for hpd based on VBT

[Jani Nikula]

On Fri, 11 Mar 2016, Shubhangi Shrivastava <shubhangi.shrivastava at intel.com> wrote:
> [ text/plain ]
> This patch sets the invert bit for hpd detection for each port
> based on VBT configuration. Since each AOB can be designed to
> depend on invert bit or not, it is expected if an AOB requires
> invert bit, the user will set respective bit in VBT.
>
> v2: Separated VBT parsing from the rest of the logic. (Jani)
>
> v3: Moved setting invert bit logic to bxt_hpd_irq_setup()
>     and changed its logic to avoid looping twice. (Ville)
>
> v4: Changed the logic to mask out the bits first and then
>     set them to remove need of temporary variable. (Ville)
>
> Signed-off-by: Sivakumar Thulasimani <sivakumar.thulasimani at intel.com>
> Signed-off-by: Durgadoss R <durgadoss.r at intel.com>
> Signed-off-by: Shubhangi Shrivastava <shubhangi.shrivastava at intel.com>
> ---
>  drivers/gpu/drm/i915/i915_drv.h   |  1 +
>  drivers/gpu/drm/i915/i915_irq.c   | 21 ++++++++++++++++++++
>  drivers/gpu/drm/i915/i915_reg.h   |  8 ++++++++
>  drivers/gpu/drm/i915/intel_bios.c | 40 +++++++++++++++++++++++++++++++++++++++
>  4 files changed, 70 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 1557d65..91963d24 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -3334,6 +3334,7 @@ extern void intel_i2c_reset(struct drm_device *dev);
>  /* intel_bios.c */
>  int intel_bios_init(struct drm_i915_private *dev_priv);
>  bool intel_bios_is_valid_vbt(const void *buf, size_t size);
> +bool intel_bios_is_port_hpd_inverted(struct drm_device *dev, enum port port);
>  
>  /* intel_opregion.c */
>  #ifdef CONFIG_ACPI
> diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
> index 53e5104..764d8f8 100644
> --- a/drivers/gpu/drm/i915/i915_irq.c
> +++ b/drivers/gpu/drm/i915/i915_irq.c
> @@ -36,6 +36,7 @@
>  #include "i915_drv.h"
>  #include "i915_trace.h"
>  #include "intel_drv.h"
> +#include "intel_bios.h"

What for? I don't think you need this.

>  
>  /**
>   * DOC: interrupt handling
> @@ -3503,6 +3504,26 @@ static void bxt_hpd_irq_setup(struct drm_device *dev)
>  	hotplug = I915_READ(PCH_PORT_HOTPLUG);
>  	hotplug |= PORTC_HOTPLUG_ENABLE | PORTB_HOTPLUG_ENABLE |
>  		PORTA_HOTPLUG_ENABLE;
> +
> +	DRM_DEBUG_KMS("Invert bit setting: hp_ctl:%x hp_port:%x\n",
> +			hotplug, enabled_irqs);
> +	hotplug &= ~BXT_DDI_HPD_INVERT_MASK;
> +
> +	/*
> +	 * 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, PORT_A))
> +		hotplug |= BXT_DDIA_HPD_INVERT;
> +	if ((enabled_irqs & BXT_DE_PORT_HP_DDIB) &&
> +	     intel_bios_is_port_hpd_inverted(dev, PORT_B))
> +		hotplug |= BXT_DDIB_HPD_INVERT;
> +	if ((enabled_irqs & BXT_DE_PORT_HP_DDIC) &&
> +	     intel_bios_is_port_hpd_inverted(dev, PORT_C))
> +		hotplug |= BXT_DDIC_HPD_INVERT;
> +
>  	I915_WRITE(PCH_PORT_HOTPLUG, hotplug);
>  }
>  
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 7dfc400..f80b870 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -6213,6 +6213,14 @@ enum skl_disp_power_wells {
>  #define  PORTB_HOTPLUG_SHORT_DETECT	(1 << 0)
>  #define  PORTB_HOTPLUG_LONG_DETECT	(2 << 0)
>  
> +/* BXT hotplug control */
> +#define BXT_DDIA_HPD_INVERT		(1 << 27)
> +#define BXT_DDIC_HPD_INVERT		(1 << 11)
> +#define BXT_DDIB_HPD_INVERT		(1 << 3)
> +#define BXT_DDI_HPD_INVERT_MASK		(BXT_DDIA_HPD_INVERT | \
> +					BXT_DDIB_HPD_INVERT | \
> +					BXT_DDIC_HPD_INVERT)
> +
>  #define PCH_PORT_HOTPLUG2		_MMIO(0xc403C)	/* SHOTPLUG_CTL2 SPT+ */
>  #define  PORTE_HOTPLUG_ENABLE		(1 << 4)
>  #define  PORTE_HOTPLUG_STATUS_MASK	(3 << 0)
> diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
> index a26d4b4..d809700 100644
> --- a/drivers/gpu/drm/i915/intel_bios.c
> +++ b/drivers/gpu/drm/i915/intel_bios.c
> @@ -105,6 +105,46 @@ find_section(const void *_bdb, int section_id)
>  	return NULL;
>  }
>  
> +bool
> +intel_bios_is_port_hpd_inverted(struct drm_device *dev, enum port port)

You should pass in dev_priv directly, nothing here needs dev.

> +{
> +	struct drm_i915_private *dev_priv = dev->dev_private;
> +	int i;
> +
> +	if (!IS_BROXTON(dev)) {
> +		DRM_ERROR("Bit inversion is not required in this platform\n");

If this happens we screwed up. If that shows up in dmesg out of context,
it's pretty ambiguous.

Please just do

	if (WARN_ON_ONCE(!IS_BROXTON(dev_priv)))
		return false;

> +		return false;
> +	}
> +
> +	for (i = 0; i < dev_priv->vbt.child_dev_num; i++) {
> +
> +		if (dev_priv->vbt.child_dev[i].common.hpd_invert == 1) {

I think this reads better and reduces indent as:

	if (!dev_priv->vbt.child_dev[i].common.hpd_invert)
        	continue;

> +
> +			switch (dev_priv->vbt.child_dev[i].common.dvo_port) {
> +			case DVO_PORT_DPA:
> +			case DVO_PORT_HDMIA:
> +				if (port == PORT_A)
> +					return true;
> +				break;
> +			case DVO_PORT_DPB:
> +			case DVO_PORT_HDMIB:
> +				if (port == PORT_B)
> +					return true;
> +				break;
> +			case DVO_PORT_DPC:
> +			case DVO_PORT_HDMIC:
> +				if (port == PORT_C)
> +					return true;
> +				break;
> +			default:
> +				break;
> +			}
> +		}
> +	}
> +
> +	return false;
> +}
> +
>  static void
>  fill_detail_timing_data(struct drm_display_mode *panel_fixed_mode,
>  			const struct lvds_dvo_timing *dvo_timing)

-- 
Jani Nikula, Intel Open Source Technology Center