Commit 989cf9a9 authored by Anshuman Gupta's avatar Anshuman Gupta Committed by Jani Nikula
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drm/i915/hdcp: Add DP HDCP2.2 timeout to read entire msg 

As documented in HDCP 2.2 DP Errata spec transmitter should abort the
authentication protocol in case transmitter has not received the
entire {AKE_Send_Cert, AKE_Send_H_prime, AKE_Send_Paring_Info} msg
within {110,7,5} miliseconds.

Adding above msg timeout values and aborting the HDCP authentication
in case it timedout to read entire msg.

https://www.digital-cp.com/sites/default/files/HDCP%202_2_DisplayPort_Errata_v3_0.pdf



v2:
- Removed redundant variable msg_can_timedout. [Ankit]

Cc: Ramalingam C <ramalingam.c@intel.com>
Signed-off-by: default avatarAnshuman Gupta <anshuman.gupta@intel.com>
Reviewed-by: default avatarAnkit Nautiyal <ankit.k.nautiyal@intel.com>
Acked-by: default avatarMaxime Ripard <mripard@kernel.org>
Signed-off-by: default avatarJani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210324113012.7564-2-anshuman.gupta@intel.com
parent 04b6603d

drivers/gpu/drm/i915/display/intel_dp_hdcp.c

+32 −13
Original line number Diff line number Diff line
@@ -294,37 +294,39 @@ struct hdcp2_dp_msg_data { 
	bool msg_detectable;

	u32 timeout;

	u32 timeout2; /* Added for non_paired situation */

	/* Timeout to read entire msg */

	u32 msg_read_timeout;

};



static const struct hdcp2_dp_msg_data hdcp2_dp_msg_data[] = {

	{ HDCP_2_2_AKE_INIT, DP_HDCP_2_2_AKE_INIT_OFFSET, false, 0, 0 },

	{ HDCP_2_2_AKE_INIT, DP_HDCP_2_2_AKE_INIT_OFFSET, false, 0, 0, 0},

	{ HDCP_2_2_AKE_SEND_CERT, DP_HDCP_2_2_AKE_SEND_CERT_OFFSET,

	  false, HDCP_2_2_CERT_TIMEOUT_MS, 0 },

	  false, HDCP_2_2_CERT_TIMEOUT_MS, 0, HDCP_2_2_DP_CERT_READ_TIMEOUT_MS},

	{ HDCP_2_2_AKE_NO_STORED_KM, DP_HDCP_2_2_AKE_NO_STORED_KM_OFFSET,

	  false, 0, 0 },

	  false, 0, 0, 0 },

	{ HDCP_2_2_AKE_STORED_KM, DP_HDCP_2_2_AKE_STORED_KM_OFFSET,

	  false, 0, 0 },

	  false, 0, 0, 0 },

	{ HDCP_2_2_AKE_SEND_HPRIME, DP_HDCP_2_2_AKE_SEND_HPRIME_OFFSET,

	  true, HDCP_2_2_HPRIME_PAIRED_TIMEOUT_MS,

	  HDCP_2_2_HPRIME_NO_PAIRED_TIMEOUT_MS },

	  HDCP_2_2_HPRIME_NO_PAIRED_TIMEOUT_MS, HDCP_2_2_DP_HPRIME_READ_TIMEOUT_MS},

	{ HDCP_2_2_AKE_SEND_PAIRING_INFO,

	  DP_HDCP_2_2_AKE_SEND_PAIRING_INFO_OFFSET, true,

	  HDCP_2_2_PAIRING_TIMEOUT_MS, 0 },

	{ HDCP_2_2_LC_INIT, DP_HDCP_2_2_LC_INIT_OFFSET, false, 0, 0 },

	  HDCP_2_2_PAIRING_TIMEOUT_MS, 0, HDCP_2_2_DP_PAIRING_READ_TIMEOUT_MS },

	{ HDCP_2_2_LC_INIT, DP_HDCP_2_2_LC_INIT_OFFSET, false, 0, 0, 0 },

	{ HDCP_2_2_LC_SEND_LPRIME, DP_HDCP_2_2_LC_SEND_LPRIME_OFFSET,

	  false, HDCP_2_2_DP_LPRIME_TIMEOUT_MS, 0 },

	  false, HDCP_2_2_DP_LPRIME_TIMEOUT_MS, 0, 0 },

	{ HDCP_2_2_SKE_SEND_EKS, DP_HDCP_2_2_SKE_SEND_EKS_OFFSET, false,

	  0, 0 },

	  0, 0, 0 },

	{ HDCP_2_2_REP_SEND_RECVID_LIST,

	  DP_HDCP_2_2_REP_SEND_RECVID_LIST_OFFSET, true,

	  HDCP_2_2_RECVID_LIST_TIMEOUT_MS, 0 },

	  HDCP_2_2_RECVID_LIST_TIMEOUT_MS, 0, 0 },

	{ HDCP_2_2_REP_SEND_ACK, DP_HDCP_2_2_REP_SEND_ACK_OFFSET, false,

	  0, 0 },

	  0, 0, 0 },

	{ HDCP_2_2_REP_STREAM_MANAGE,

	  DP_HDCP_2_2_REP_STREAM_MANAGE_OFFSET, false,

	  0, 0 },

	  0, 0, 0},

	{ HDCP_2_2_REP_STREAM_READY, DP_HDCP_2_2_REP_STREAM_READY_OFFSET,

	  false, HDCP_2_2_STREAM_READY_TIMEOUT_MS, 0 },

	  false, HDCP_2_2_STREAM_READY_TIMEOUT_MS, 0, 0 },

/* local define to shovel this through the write_2_2 interface */

#define HDCP_2_2_ERRATA_DP_STREAM_TYPE	50

	{ HDCP_2_2_ERRATA_DP_STREAM_TYPE,
@@ -530,6 +532,8 @@ int intel_dp_hdcp2_read_msg(struct intel_digital_port *dig_port, 
	u8 *byte = buf;

	ssize_t ret, bytes_to_recv, len;

	const struct hdcp2_dp_msg_data *hdcp2_msg_data;

	ktime_t msg_end;

	bool msg_expired;



	hdcp2_msg_data = get_hdcp2_dp_msg_data(msg_id);

	if (!hdcp2_msg_data)
@@ -556,6 +560,11 @@ int intel_dp_hdcp2_read_msg(struct intel_digital_port *dig_port, 
		len = bytes_to_recv > DP_AUX_MAX_PAYLOAD_BYTES ?

		      DP_AUX_MAX_PAYLOAD_BYTES : bytes_to_recv;



		/* Entire msg read timeout since initiate of msg read */

		if (bytes_to_recv == size - 1 && hdcp2_msg_data->msg_read_timeout > 0)

			msg_end = ktime_add_ms(ktime_get_raw(),

					       hdcp2_msg_data->msg_read_timeout);



		ret = drm_dp_dpcd_read(&dig_port->dp.aux, offset,

				       (void *)byte, len);

		if (ret < 0) {
@@ -568,6 +577,16 @@ int intel_dp_hdcp2_read_msg(struct intel_digital_port *dig_port, 
		byte += ret;

		offset += ret;

	}



	if (hdcp2_msg_data->msg_read_timeout > 0) {

		msg_expired = ktime_after(ktime_get_raw(), msg_end);

		if (msg_expired) {

			drm_dbg_kms(&i915->drm, "msg_id %d, entire msg read timeout(mSec): %d\n",

				    msg_id, hdcp2_msg_data->msg_read_timeout);

			return -ETIMEDOUT;

		}

	}



	byte = buf;

	*byte = msg_id;

include/drm/drm_hdcp.h

+3 −0
Original line number Diff line number Diff line
@@ -224,9 +224,12 @@ struct hdcp2_rep_stream_ready { 


/* HDCP2.2 TIMEOUTs in mSec */

#define HDCP_2_2_CERT_TIMEOUT_MS		100

#define HDCP_2_2_DP_CERT_READ_TIMEOUT_MS	110

#define HDCP_2_2_HPRIME_NO_PAIRED_TIMEOUT_MS	1000

#define HDCP_2_2_HPRIME_PAIRED_TIMEOUT_MS	200

#define HDCP_2_2_DP_HPRIME_READ_TIMEOUT_MS	7

#define HDCP_2_2_PAIRING_TIMEOUT_MS		200

#define HDCP_2_2_DP_PAIRING_READ_TIMEOUT_MS	5

#define	HDCP_2_2_HDMI_LPRIME_TIMEOUT_MS		20

#define HDCP_2_2_DP_LPRIME_TIMEOUT_MS		7

#define HDCP_2_2_RECVID_LIST_TIMEOUT_MS		3000