[Intel-gfx] [PATCH] drm/i915: HDCP: fix Ri prime check done during link check

[Ramalingam C]

On 2020-02-29 at 11:39:22 +0100, Oliver Barta wrote:
> From: Oliver Barta <oliver.barta at aptiv.com>
> 
> The check was always succeeding even in case of a mismatch due to the
> HDCP_STATUS_ENC bit being set. Make sure both bits are actually set.
> 
> Signed-off-by: Oliver Barta <oliver.barta at aptiv.com>
Looks good to me. But we need to do same on intel_hdcp_auth(), where we
check the R0 on authentication.

-Ram
> Fixes: 2320175feb74 ("drm/i915: Implement HDCP for HDMI")
> ---
>  Submitted before as part of patch series
>  https://patchwork.freedesktop.org/series/73961/
>  For some reason the versioning got messed up. 
>  I marked the patch series as superseded and I'm
>  starting all over. Sorry for spamming you.
> 
>  drivers/gpu/drm/i915/display/intel_hdmi.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_hdmi.c b/drivers/gpu/drm/i915/display/intel_hdmi.c
> index 0ac9bdfbc094..ac4276157182 100644
> --- a/drivers/gpu/drm/i915/display/intel_hdmi.c
> +++ b/drivers/gpu/drm/i915/display/intel_hdmi.c
> @@ -1536,7 +1536,8 @@ bool intel_hdmi_hdcp_check_link(struct intel_digital_port *intel_dig_port)
>  	intel_de_write(i915, HDCP_RPRIME(i915, cpu_transcoder, port), ri.reg);
>  
>  	/* Wait for Ri prime match */
> -	if (wait_for(intel_de_read(i915, HDCP_STATUS(i915, cpu_transcoder, port)) &
> +	if (wait_for((intel_de_read(i915, HDCP_STATUS(i915, cpu_transcoder,
> +		     port)) & (HDCP_STATUS_RI_MATCH | HDCP_STATUS_ENC)) ==
>  		     (HDCP_STATUS_RI_MATCH | HDCP_STATUS_ENC), 1)) {
>  		DRM_ERROR("Ri' mismatch detected, link check failed (%x)\n",
>  			  intel_de_read(i915, HDCP_STATUS(i915, cpu_transcoder, port)));
> -- 
> 2.20.1
>