[Intel-gfx] [PATCH v3 1/4] drm/i915: Pullout the bksv read and validation

[Daniel Vetter]

On Mon, Oct 22, 2018 at 07:46:02PM +0530, Ramalingam C wrote:
> For reusability purpose, this patch implements the hdcp1.4 bksv's
> read and validation as a functions.
> 
> For detecting the HDMI panel's HDCP capability this fucntions will be
> used.
> 
> v2:
>   Rebased.
> v3:
>   No Changes.
> v4:
>   inline tag is removed with modified error msg.
> v5:
>   No Changes.
> v6:
>   No Changes.
> v7:
>   Realigned the code.
> 
> Signed-off-by: Ramalingam C <ramalingam.c at intel.com>
> Reviewed-by: Sean Paul <seanpaul at chromium.org>

Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>

> ---
>  drivers/gpu/drm/i915/intel_hdcp.c | 62 ++++++++++++++++++++++++---------------
>  1 file changed, 38 insertions(+), 24 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_hdcp.c b/drivers/gpu/drm/i915/intel_hdcp.c
> index 26e48fc95543..20908ff018e6 100644
> --- a/drivers/gpu/drm/i915/intel_hdcp.c
> +++ b/drivers/gpu/drm/i915/intel_hdcp.c
> @@ -16,6 +16,41 @@
>  
>  #define KEY_LOAD_TRIES	5
>  
> +static
> +bool intel_hdcp_is_ksv_valid(u8 *ksv)
> +{
> +	int i, ones = 0;
> +	/* KSV has 20 1's and 20 0's */
> +	for (i = 0; i < DRM_HDCP_KSV_LEN; i++)
> +		ones += hweight8(ksv[i]);
> +	if (ones != 20)
> +		return false;
> +
> +	return true;
> +}
> +
> +static
> +int intel_hdcp_read_valid_bksv(struct intel_digital_port *intel_dig_port,
> +			       const struct intel_hdcp_shim *shim, u8 *bksv)
> +{
> +	int ret, i, tries = 2;
> +
> +	/* HDCP spec states that we must retry the bksv if it is invalid */
> +	for (i = 0; i < tries; i++) {
> +		ret = shim->read_bksv(intel_dig_port, bksv);
> +		if (ret)
> +			return ret;
> +		if (intel_hdcp_is_ksv_valid(bksv))
> +			break;
> +	}
> +	if (i == tries) {
> +		DRM_ERROR("Bksv is invalid\n");
> +		return -ENODEV;
> +	}
> +
> +	return 0;
> +}
> +
>  static int intel_hdcp_poll_ksv_fifo(struct intel_digital_port *intel_dig_port,
>  				    const struct intel_hdcp_shim *shim)
>  {
> @@ -168,18 +203,6 @@ u32 intel_hdcp_get_repeater_ctl(struct intel_digital_port *intel_dig_port)
>  }
>  
>  static
> -bool intel_hdcp_is_ksv_valid(u8 *ksv)
> -{
> -	int i, ones = 0;
> -	/* KSV has 20 1's and 20 0's */
> -	for (i = 0; i < DRM_HDCP_KSV_LEN; i++)
> -		ones += hweight8(ksv[i]);
> -	if (ones != 20)
> -		return false;
> -	return true;
> -}
> -
> -static
>  int intel_hdcp_validate_v_prime(struct intel_digital_port *intel_dig_port,
>  				const struct intel_hdcp_shim *shim,
>  				u8 *ksv_fifo, u8 num_downstream, u8 *bstatus)
> @@ -527,18 +550,9 @@ static int intel_hdcp_auth(struct intel_digital_port *intel_dig_port,
>  
>  	memset(&bksv, 0, sizeof(bksv));
>  
> -	/* HDCP spec states that we must retry the bksv if it is invalid */
> -	for (i = 0; i < tries; i++) {
> -		ret = shim->read_bksv(intel_dig_port, bksv.shim);
> -		if (ret)
> -			return ret;
> -		if (intel_hdcp_is_ksv_valid(bksv.shim))
> -			break;
> -	}
> -	if (i == tries) {
> -		DRM_ERROR("HDCP failed, Bksv is invalid\n");
> -		return -ENODEV;
> -	}
> +	ret = intel_hdcp_read_valid_bksv(intel_dig_port, shim, bksv.shim);
> +	if (ret < 0)
> +		return ret;
>  
>  	I915_WRITE(PORT_HDCP_BKSVLO(port), bksv.reg[0]);
>  	I915_WRITE(PORT_HDCP_BKSVHI(port), bksv.reg[1]);
> -- 
> 2.7.4
> 

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