[PATCH v8 33/35] drm/i915: Fix KBL HDCP2.2 encrypt status signalling

[Daniel Vetter]

On Tue, Nov 27, 2018 at 04:13:31PM +0530, Ramalingam C wrote:
> Implement the required WA sequence for KBL to fix the
> incorrect positioning of the window of oppurtunity and enc_en
> signalling.
> 
> Signed-off-by: Ramalingam C <ramalingam.c at intel.com>
> ---
>  drivers/gpu/drm/i915/intel_hdcp.c | 29 +++++++++++++++++++++++++++++
>  1 file changed, 29 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/intel_hdcp.c b/drivers/gpu/drm/i915/intel_hdcp.c
> index 9f4056e156ec..654a076c58e4 100644
> --- a/drivers/gpu/drm/i915/intel_hdcp.c
> +++ b/drivers/gpu/drm/i915/intel_hdcp.c
> @@ -12,6 +12,7 @@
>  #include <linux/i2c.h>
>  #include <linux/random.h>
>  #include <linux/component.h>
> +#include <linux/delay.h>
>  
>  #include "intel_drv.h"
>  #include "i915_reg.h"
> @@ -24,6 +25,27 @@
>  	__p == PORT_A ? MEI_DDI_A : (enum mei_hdcp_ddi)__p;\
>  })
>  
> +static void kbl_repositioning_enc_en_signal(struct intel_connector *connector)

Is there a Bspec WA number/label so I can more easily find this?
-Daniel

> +{
> +	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
> +	struct intel_digital_port *intel_dig_port = conn_to_dig_port(connector);
> +	struct intel_hdcp *hdcp = &connector->hdcp;
> +	struct drm_crtc *crtc = connector->base.state->crtc;
> +	struct intel_crtc *intel_crtc = container_of(crtc,
> +						     struct intel_crtc, base);
> +	u32 scanline;
> +
> +	for (;;) {
> +		scanline = I915_READ(PIPEDSL(intel_crtc->pipe));
> +		if (scanline > 100 && scanline < 200)
> +			break;
> +		usleep_range(25, 50);
> +	}
> +
> +	hdcp->shim->toggle_signalling(intel_dig_port, false);
> +	hdcp->shim->toggle_signalling(intel_dig_port, true);
> +}
> +
>  static
>  bool intel_hdcp_is_ksv_valid(u8 *ksv)
>  {
> @@ -1527,6 +1549,13 @@ static int hdcp2_enable_encryption(struct intel_connector *connector)
>  	}
>  
>  	if (I915_READ(HDCP2_STATUS_DDI(port)) & LINK_AUTH_STATUS) {
> +		/*
> +		 * WA: To fix incorrect positioning of the window of
> +		 * opportunity and enc_en signalling in KABYLAKE.
> +		 */
> +		if (IS_KABYLAKE(dev_priv) && hdcp->shim->toggle_signalling)
> +			kbl_repositioning_enc_en_signal(connector);
> +
>  		/* Link is Authenticated. Now set for Encryption */
>  		I915_WRITE(HDCP2_CTL_DDI(port),
>  			   I915_READ(HDCP2_CTL_DDI(port)) |
> -- 
> 2.7.4
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch