[Intel-gfx] [PATCH v3 32/40] drm/i915: Enable superior HDCP ver that is capable

[Ramalingam C]

On Friday 18 May 2018 06:19 PM, Shankar, Uma wrote:
>
>> -----Original Message-----
>> From: Intel-gfx [mailto:intel-gfx-bounces at lists.freedesktop.org] On Behalf Of
>> Ramalingam C
>> Sent: Tuesday, April 3, 2018 7:28 PM
>> To: intel-gfx at lists.freedesktop.org; dri-devel at lists.freedesktop.org;
>> seanpaul at chromium.org; daniel at ffwll.ch; chris at chris-wilson.co.uk;
>> jani.nikula at linux.intel.com; Winkler, Tomas <tomas.winkler at intel.com>;
>> Usyskin, Alexander <alexander.usyskin at intel.com>
>> Cc: Vivi, Rodrigo <rodrigo.vivi at intel.com>
>> Subject: [Intel-gfx] [PATCH v3 32/40] drm/i915: Enable superior HDCP ver that is
>> capable
>>
>> Considering that HDCP2.2 is more secure than HDCP1.4, When a setup supports
>> HDCP2.2 and HDCP1.4, HDCP2.2 will be enabled.
>>
>> v2:
>>   Included few optimization suggestions [Chris Wilson]
>>   Commit message is updated as per the rebased version.
>> v3:
>>   No changes.
>>
>> Signed-off-by: Ramalingam C <ramalingam.c at intel.com>
>> ---
>> drivers/gpu/drm/i915/intel_hdcp.c | 76
>> +++++++++++++++++++++++++++++++++++----
>> 1 file changed, 69 insertions(+), 7 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/intel_hdcp.c
>> b/drivers/gpu/drm/i915/intel_hdcp.c
>> index 383e35689fbd..01701d7b7b07 100644
>> --- a/drivers/gpu/drm/i915/intel_hdcp.c
>> +++ b/drivers/gpu/drm/i915/intel_hdcp.c
>> @@ -27,6 +27,57 @@ static int _intel_hdcp2_disable(struct intel_connector
>> *connector);  static void intel_hdcp2_check_work(struct work_struct *work);
>> static int intel_hdcp2_check_link(struct intel_connector *connector);  static int
>> intel_hdcp2_init(struct intel_connector *connector);
>> +static inline
>> +int intel_hdcp_read_valid_bksv(struct intel_digital_port *intel_dig_port,
>> +			       const struct intel_hdcp_shim *shim, u8 *bksv); static
>> struct
>> +intel_digital_port *conn_to_dig_port(struct intel_connector
>> +*connector);
>> +
>> +static inline
> Don’t have it as inline.
>
>> +bool panel_supports_hdcp(struct intel_connector *connector) {
>> +	struct intel_digital_port *intel_dig_port = conn_to_dig_port(connector);
>> +	struct intel_hdcp *hdcp = &connector->hdcp;
>> +	bool capable = false;
>> +	u8 bksv[5];
>> +
>> +	if (hdcp->hdcp_shim) {
>> +		if (hdcp->hdcp_shim->hdcp_capable) {
>> +			hdcp->hdcp_shim->hdcp_capable(intel_dig_port,
>> &capable);
>> +		} else {
>> +			if (!intel_hdcp_read_valid_bksv(intel_dig_port,
>> +							hdcp->hdcp_shim,
>> bksv))
>> +				capable = true;
>> +		}
>> +	}
> Leave a blank line.
>
>> +	return capable;
>> +}
>> +
>> +static inline
>> +bool panel_supports_hdcp2(struct intel_connector *connector) {
>> +	struct intel_digital_port *intel_dig_port = conn_to_dig_port(connector);
>> +	struct intel_hdcp *hdcp = &connector->hdcp;
>> +	bool capable = false;
>> +
>> +	if (hdcp->hdcp2_supported)
>> +		hdcp->hdcp_shim->hdcp_2_2_capable(intel_dig_port, &capable);
> This looks a bit odd. We are going inside if hdcp2.2 is supported and checking for capable.
> I guess it needs a bit of renaming to make them implicit(Supported and capable sounds
> confusing). I believe supported is for platform and capable is for panel ?
As function name says, here we are checking the panel's hdcp2.2 
compliance if the platform supports it.
I will add Explicit comment here.

Ram
>
>> +
>> +	return capable;
>> +}
>> +
>> +/* Is HDCP1.4 capable on Platform and Panel */ static inline bool
>> +intel_hdcp_capable(struct intel_connector *connector) {
>> +	return (connector->hdcp.hdcp_shim &&
>> panel_supports_hdcp(connector));
>> +}
>> +
>> +/* Is HDCP2.2 capable on Platform and Panel */ static inline bool
>> +intel_hdcp2_capable(struct intel_connector *connector) {
>> +	return (connector->hdcp.hdcp2_supported &&
>> +		panel_supports_hdcp2(connector));
>> +}
>>
>> static int intel_hdcp_poll_ksv_fifo(struct intel_digital_port *intel_dig_port,
>> 				    const struct intel_hdcp_shim *shim) @@ -
>> 722,20 +773,27 @@ int intel_hdcp_init(struct intel_connector *connector,  int
>> intel_hdcp_enable(struct intel_connector *connector)  {
>> 	struct intel_hdcp *hdcp = &connector->hdcp;
>> -	int ret;
>> +	int ret = -EINVAL;
>>
>> 	if (!hdcp->hdcp_shim)
>> 		return -ENOENT;
>>
>> 	mutex_lock(&hdcp->hdcp_mutex);
>>
>> -	ret = _intel_hdcp_enable(connector);
>> -	if (ret)
>> -		goto out;
>> +	/*
>> +	 * Considering that HDCP2.2 is more secure than HDCP1.4, If the setup
>> +	 * is capable of HDCP2.2, it is preferred to use HDCP2.2.
>> +	 */
>> +	if (intel_hdcp2_capable(connector))
>> +		ret = _intel_hdcp2_enable(connector);
>> +	else if (intel_hdcp_capable(connector))
>> +		ret = _intel_hdcp_enable(connector);
>> +
>> +	if (!ret) {
>> +		hdcp->hdcp_value =
>> DRM_MODE_CONTENT_PROTECTION_ENABLED;
>> +		schedule_work(&hdcp->hdcp_prop_work);
>> +	}
>>
>> -	hdcp->hdcp_value = DRM_MODE_CONTENT_PROTECTION_ENABLED;
>> -	schedule_work(&hdcp->hdcp_prop_work);
>> -out:
>> 	mutex_unlock(&hdcp->hdcp_mutex);
>> 	return ret;
>> }
>> @@ -752,10 +810,14 @@ int intel_hdcp_disable(struct intel_connector
>> *connector)
>>
>> 	if (hdcp->hdcp_value !=
>> DRM_MODE_CONTENT_PROTECTION_UNDESIRED) {
>> 		hdcp->hdcp_value =
>> DRM_MODE_CONTENT_PROTECTION_UNDESIRED;
>> +		if (hdcp->hdcp2_supported)
>> +			_intel_hdcp2_disable(connector);
>> +
>> 		ret = _intel_hdcp_disable(connector);
>> 	}
>>
>> 	mutex_unlock(&hdcp->hdcp_mutex);
>> +	cancel_delayed_work_sync(&hdcp->hdcp2_check_work);
>> 	cancel_delayed_work_sync(&hdcp->hdcp_check_work);
>> 	return ret;
>> }
>> --
>> 2.7.4
>>
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