Re: [PATCH v2 1/2] drm/i915/hdcp: Add DP HDCP2.2 timeout to read entire msg

LGTM.

Reviewed-by: Ankit Nautiyal ankit.k.nautiyal@intel.com

On 3/24/2021 5:00 PM, Anshuman Gupta wrote:

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...

v2:

• Removed redundant variable msg_can_timedout. [Ankit]

Cc: Ramalingam C ramalingam.c@intel.com Signed-off-by: Anshuman Gupta anshuman.gupta@intel.com

---

drivers/gpu/drm/i915/display/intel_dp_hdcp.c | 45 ++++++++++++++------ include/drm/drm_hdcp.h | 3 ++ 2 files changed, 35 insertions(+), 13 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_dp_hdcp.c b/drivers/gpu/drm/i915/display/intel_dp_hdcp.c index 40c516e90193..8bad4b3d34dd 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_hdcp.c +++ b/drivers/gpu/drm/i915/display/intel_dp_hdcp.c @@ -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,

@@ -513,6 +515,8 @@ 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)

@@ -539,6 +543,11 @@ 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) {

@@ -551,6 +560,16 @@ 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;

diff --git a/include/drm/drm_hdcp.h b/include/drm/drm_hdcp.h index ac22c246542a..2b165a0f434f 100644 --- a/include/drm/drm_hdcp.h +++ b/include/drm/drm_hdcp.h @@ -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