Re: [PATCH v6 02/16] drm/i915: Clear the repeater bit on HDCP disable

[Ramalingam C <ramalingam.c@intel.com>]

On 2020-04-29 at 15:54:48 -0400, Sean Paul wrote:
> From: Sean Paul <seanpaul@chromium.org>
> 
> On HDCP disable, clear the repeater bit. This ensures if we connect a
> non-repeater sink after a repeater, the bit is in the state we expect.
> 
> Fixes: ee5e5e7a5e0f (drm/i915: Add HDCP framework + base implementation)
> Cc: Chris Wilson <chris@chris-wilson.co.uk>
> Cc: Ramalingam C <ramalingam.c@intel.com>
> Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
> Cc: Sean Paul <seanpaul@chromium.org>
> Cc: Jani Nikula <jani.nikula@linux.intel.com>
> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
> Cc: intel-gfx@lists.freedesktop.org
> Cc: <stable@vger.kernel.org> # v4.17+
> Reviewed-by: Ramalingam C <ramalingam.c@intel.com>
Just reconfirming my R-b here.

Reviewed-by: Ramalingam C <ramalingam.c@intel.com>
> Signed-off-by: Sean Paul <seanpaul@chromium.org>
> Link: https://patchwork.freedesktop.org/patch/msgid/20191212190230.188505-3-sean@poorly.run #v2
> Link: https://patchwork.freedesktop.org/patch/msgid/20200117193103.156821-3-sean@poorly.run #v3
> Link: https://patchwork.freedesktop.org/patch/msgid/20200218220242.107265-3-sean@poorly.run #v4
> Link: https://patchwork.freedesktop.org/patch/msgid/20200305201236.152307-3-sean@poorly.run #v5
> 
> Changes in v2:
> -Added to the set
> Changes in v3:
> -None
>   I had previously agreed that clearing the rep_ctl bits on enable would
>   also be a good idea. However when I committed that idea to code, it
>   didn't look right. So let's rely on enables and disables being paired
>   and everything outside of that will be considered a bug
> Changes in v4:
> -s/I915_(READ|WRITE)/intel_de_(read|write)/
> Changes in v5:
> -None
> Changes in v6:
> -None
> ---
>  drivers/gpu/drm/i915/display/intel_hdcp.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_hdcp.c b/drivers/gpu/drm/i915/display/intel_hdcp.c
> index 525658fd201f..20175a53643d 100644
> --- a/drivers/gpu/drm/i915/display/intel_hdcp.c
> +++ b/drivers/gpu/drm/i915/display/intel_hdcp.c
> @@ -795,6 +795,7 @@ static int _intel_hdcp_disable(struct intel_connector *connector)
>  	struct intel_hdcp *hdcp = &connector->hdcp;
>  	enum port port = intel_dig_port->base.port;
>  	enum transcoder cpu_transcoder = hdcp->cpu_transcoder;
> +	u32 repeater_ctl;
>  	int ret;
>  
>  	drm_dbg_kms(&dev_priv->drm, "[%s:%d] HDCP is being disabled...\n",
> @@ -810,6 +811,11 @@ static int _intel_hdcp_disable(struct intel_connector *connector)
>  		return -ETIMEDOUT;
>  	}
>  
> +	repeater_ctl = intel_hdcp_get_repeater_ctl(dev_priv, cpu_transcoder,
> +						   port);
> +	intel_de_write(dev_priv, HDCP_REP_CTL,
> +		       intel_de_read(dev_priv, HDCP_REP_CTL) & ~repeater_ctl);
> +
>  	ret = hdcp->shim->toggle_signalling(intel_dig_port, false);
>  	if (ret) {
>  		drm_err(&dev_priv->drm, "Failed to disable HDCP signalling\n");
> -- 
> Sean Paul, Software Engineer, Google / Chromium OS
>