[Intel-gfx] [PATCH] drm/i915: Check live status before reading edid

[Daniel Vetter]

On Mon, Jul 13, 2015 at 04:35:00PM +0530, Sonika Jindal wrote:
> Adding this for SKL onwards.
> 
> v2: Adding checks for VLV/CHV as well. Reusing old ibx and g4x functions
> to check digital port status. Adding a separate function to get bxt live
> status (Daniel)
> 
> Signed-off-by: Sonika Jindal <sonika.jindal at intel.com>
> ---
>  drivers/gpu/drm/i915/intel_dp.c   |    4 ++--
>  drivers/gpu/drm/i915/intel_drv.h  |    2 ++
>  drivers/gpu/drm/i915/intel_hdmi.c |   42 +++++++++++++++++++++++++++++++++----
>  3 files changed, 42 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> index 4ebfc3a..7b54b9d 100644
> --- a/drivers/gpu/drm/i915/intel_dp.c
> +++ b/drivers/gpu/drm/i915/intel_dp.c
> @@ -4443,8 +4443,8 @@ ironlake_dp_detect(struct intel_dp *intel_dp)
>  	return intel_dp_detect_dpcd(intel_dp);
>  }
>  
> -static int g4x_digital_port_connected(struct drm_device *dev,
> -				       struct intel_digital_port *intel_dig_port)
> +int g4x_digital_port_connected(struct drm_device *dev,
> +			       struct intel_digital_port *intel_dig_port)
>  {
>  	struct drm_i915_private *dev_priv = dev->dev_private;
>  	uint32_t bit;
> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> index a47fbc3..30c8dd6 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -1187,6 +1187,8 @@ void intel_edp_drrs_disable(struct intel_dp *intel_dp);
>  void intel_edp_drrs_invalidate(struct drm_device *dev,
>  		unsigned frontbuffer_bits);
>  void intel_edp_drrs_flush(struct drm_device *dev, unsigned frontbuffer_bits);
> +int g4x_digital_port_connected(struct drm_device *dev,
> +			       struct intel_digital_port *intel_dig_port);
>  
>  /* intel_dp_mst.c */
>  int intel_dp_mst_encoder_init(struct intel_digital_port *intel_dig_port, int conn_id);
> diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
> index 1fb6919..7eb0d0e 100644
> --- a/drivers/gpu/drm/i915/intel_hdmi.c
> +++ b/drivers/gpu/drm/i915/intel_hdmi.c
> @@ -1300,6 +1300,39 @@ intel_hdmi_unset_edid(struct drm_connector *connector)
>  	to_intel_connector(connector)->detect_edid = NULL;
>  }
>  
> +static bool bxt_port_connected(struct drm_i915_private *dev_priv,
> +			       struct intel_digital_port *port)
> +{
> +	u32 temp = I915_READ(GEN8_DE_PORT_ISR);
> +
> +	switch (port->port) {
> +	case PORT_B:
> +		return temp & BXT_DE_PORT_HP_DDIB;
> +
> +	case PORT_C:
> +		return temp & BXT_DE_PORT_HP_DDIC;
> +
> +	default:
> +		return false;
> +
> +	}
> +}
> +
> +static bool intel_hdmi_live_status(struct intel_digital_port *intel_dig_port)
> +{
> +	struct drm_device *dev = intel_dig_port->base.base.dev;
> +	struct drm_i915_private *dev_priv = to_i915(dev);
> +
> +	if (IS_VALLEYVIEW(dev))
> +		return g4x_digital_port_connected(dev, intel_dig_port);
> +	else if (IS_SKYLAKE(dev))
> +		return ibx_digital_port_connected(dev_priv, intel_dig_port);
> +	else if (IS_BROXTON(dev))
> +		return bxt_port_connected(dev_priv, intel_dig_port);

Really I want this to be rolled out for all platforms, together with the
fix for handling hpd interrupts. Together with a reference to the old
commits we had to revert because it didn't work.

I want to test this on my ivb (since that's the machine where I can
readily reproduce this bug), and if it still doesn't work there I won't
take this.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch