[PATCH v4 38/41] drm/i915: Implement the HDCP2.2 support for DP
Daniel Vetter
daniel at ffwll.ch
Wed Jun 20 11:43:34 UTC 2018
On Wed, Jun 20, 2018 at 12:19 PM, Ramalingam C <ramalingam.c at intel.com> wrote:
>
>
> On Thursday 31 May 2018 12:52 PM, Daniel Vetter wrote:
>>
>> On Mon, May 21, 2018 at 06:23:57PM +0530, Ramalingam C wrote:
>>>
>>> Implements the DP adaptation specific HDCP2.2 functions.
>>>
>>> These functions perform the DPCD read and write for communicating the
>>> HDCP2.2 auth message back and forth.
>>>
>>> Note: Chris Wilson suggested alternate method for waiting for CP_IRQ,
>>> than completions concept. WIP to understand and implement that,
>>> if needed. Just to unblock the review of other changes, v2 still
>>> continues with completions.
>>>
>>> v2:
>>> wait for cp_irq is merged with this patch. Rebased.
>>> v3:
>>> wait_queue is used for wait for cp_irq [Chris Wilson]
>>> v4:
>>> Style fixed.
>>> %s/PARING/PAIRING
>>> Few style fixes [Uma]
>>>
>>> Signed-off-by: Ramalingam C <ramalingam.c at intel.com>
>>> ---
>>> drivers/gpu/drm/i915/intel_dp.c | 358
>>> ++++++++++++++++++++++++++++++++++++++
>>> drivers/gpu/drm/i915/intel_drv.h | 7 +
>>> drivers/gpu/drm/i915/intel_hdcp.c | 5 +
>>> 3 files changed, 370 insertions(+)
>>>
>>> diff --git a/drivers/gpu/drm/i915/intel_dp.c
>>> b/drivers/gpu/drm/i915/intel_dp.c
>>> index 528407d608c8..ee71a26ec23f 100644
>>> --- a/drivers/gpu/drm/i915/intel_dp.c
>>> +++ b/drivers/gpu/drm/i915/intel_dp.c
>>> @@ -31,6 +31,7 @@
>>> #include <linux/types.h>
>>> #include <linux/notifier.h>
>>> #include <linux/reboot.h>
>>> +#include <linux/mei_hdcp.h>
>>> #include <asm/byteorder.h>
>>> #include <drm/drmP.h>
>>> #include <drm/drm_atomic_helper.h>
>>> @@ -5057,6 +5058,28 @@ void intel_dp_encoder_suspend(struct intel_encoder
>>> *intel_encoder)
>>> pps_unlock(intel_dp);
>>> }
>>> +static int intel_dp_hdcp_wait_for_cp_irq(struct intel_hdcp *hdcp,
>>> + int timeout)
>>> +{
>>> + long ret;
>>> +
>>> + /* Reinit */
>>> + atomic_set(&hdcp->cp_irq_recved, 0);
>>> +
>>> +#define C (atomic_read(&hdcp->cp_irq_recved) > 0)
>>> + ret = wait_event_interruptible_timeout(hdcp->cp_irq_queue, C,
>>> +
>>> msecs_to_jiffies(timeout));
>>> +
>>> + if (ret > 0) {
>>> + atomic_set(&hdcp->cp_irq_recved, 0);
>>> + return 0;
>>> + } else if (!ret) {
>>> + return -ETIMEDOUT;
>>> + }
>>> + return (int)ret;
>>> +}
>>> +
>>> +
>>> static
>>> int intel_dp_hdcp_write_an_aksv(struct intel_digital_port
>>> *intel_dig_port,
>>> u8 *an)
>>> @@ -5275,6 +5298,335 @@ int intel_dp_hdcp_capable(struct
>>> intel_digital_port *intel_dig_port,
>>> return 0;
>>> }
>>> +static
>>> +int intel_dpcd_offset_for_hdcp2_msgid(uint8_t byte, unsigned int
>>> *offset)
>>
>> Ugh, this is annoying that we have to map things around like that. But
>> looking at the numbers the standards really don't seem to match at all.
>
> Sorry i am not getting about not matching part.
> You mean some offsets and timeouts are not matching with spec?
match as in you can't just compute them using a base_offset +
hdcp_msgid trick, you do have to use the lookup table. The numbers
itself match the spec, it's just that the specs are all inconsistent
with each another for no real good reason.
>>
>>
>> Instead of open-coding this I suggested you use a table with a struct
>> like:
>>
>> const static struct hdcp_dp {
>> int hdcp_msg;
>> int dpcd_offset;
>> int timeout;
>> /* whatever else you might need */
>> } hdcp_2_dp_table[] = {
>> { HDCP_2_2_AKE_INIT, DP_HDCP_2_2_AKE_INIT_OFFSET, ... },
>> ...
>> };
>>
>> Then just search that table in the code instead of the huge switch table
>> below.
>
> Suggesting this for cpu optimization or for coding style?
Just coding style, having to check a table is easier than checking
huge case statements. None of this code matters from a performance
pov.
>
>
>>
>>> +{
>>> + switch (byte) {
>>> + case HDCP_2_2_AKE_INIT:
>>> + *offset = DP_HDCP_2_2_AKE_INIT_OFFSET;
>>> + break;
>>> + case HDCP_2_2_AKE_SEND_CERT:
>>> + *offset = DP_HDCP_2_2_AKE_SEND_CERT_OFFSET;
>>> + break;
>>> + case HDCP_2_2_AKE_NO_STORED_KM:
>>> + *offset = DP_HDCP_2_2_AKE_NO_STORED_KM_OFFSET;
>>> + break;
>>> + case HDCP_2_2_AKE_STORED_KM:
>>> + *offset = DP_HDCP_2_2_AKE_STORED_KM_OFFSET;
>>> + break;
>>> + case HDCP_2_2_AKE_SEND_HPRIME:
>>> + *offset = DP_HDCP_2_2_AKE_SEND_HPRIME_OFFSET;
>>> + break;
>>> + case HDCP_2_2_AKE_SEND_PAIRING_INFO:
>>> + *offset = DP_HDCP_2_2_AKE_SEND_PAIRING_INFO_OFFSET;
>>> + break;
>>> + case HDCP_2_2_LC_INIT:
>>> + *offset = DP_HDCP_2_2_LC_INIT_OFFSET;
>>> + break;
>>> + case HDCP_2_2_LC_SEND_LPRIME:
>>> + *offset = DP_HDCP_2_2_LC_SEND_LPRIME_OFFSET;
>>> + break;
>>> + case HDCP_2_2_SKE_SEND_EKS:
>>> + *offset = DP_HDCP_2_2_SKE_SEND_EKS_OFFSET;
>>> + break;
>>> + case HDCP_2_2_REP_SEND_RECVID_LIST:
>>> + *offset = DP_HDCP_2_2_REP_SEND_RECVID_LIST_OFFSET;
>>> + break;
>>> + case HDCP_2_2_REP_SEND_ACK:
>>> + *offset = DP_HDCP_2_2_REP_SEND_ACK_OFFSET;
>>> + break;
>>> + case HDCP_2_2_REP_STREAM_MANAGE:
>>> + *offset = DP_HDCP_2_2_REP_STREAM_MANAGE_OFFSET;
>>> + break;
>>> + case HDCP_2_2_REP_STREAM_READY:
>>> + *offset = DP_HDCP_2_2_REP_STREAM_READY_OFFSET;
>>> + break;
>>> + case HDCP_2_2_ERRATA_DP_STREAM_TYPE:
>>> + *offset = DP_HDCP_2_2_REG_STREAM_TYPE_OFFSET;
>>> + break;
>>> + default:
>>> + DRM_ERROR("Unrecognized Msg ID\n");
>>> + return -EINVAL;
>>> + }
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static inline
>>> +int intel_dp_hdcp2_read_rx_status(struct intel_digital_port
>>> *intel_dig_port,
>>> + uint8_t *rx_status)
>>> +{
>>> + ssize_t ret;
>>> +
>>> + ret = drm_dp_dpcd_read(&intel_dig_port->dp.aux,
>>> + DP_HDCP_2_2_REG_RXSTATUS_OFFSET,
>>> rx_status,
>>> + HDCP_2_2_DP_RXSTATUS_LEN);
>>> + if (ret != HDCP_2_2_DP_RXSTATUS_LEN) {
>>> + DRM_ERROR("Read bstatus from DP/AUX failed (%ld)\n",
>>> ret);
>>> + return ret >= 0 ? -EIO : ret;
>>> + }
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static
>>> +int intel_dp_hdcp2_timeout_for_msg(uint8_t msg_id, bool paired)
>>
>> For the timeout and the availability check below, is that not the same for
>> hdmi? Might be good to set the timeout/check values once, and perhaps pass
>> that then down to the dp/hdmi implementation, instead of computing it
>> here.
>>
>> All these functions here look like a huge layering violation. Imo all this
>> timeout stuff should be handled higher up, or at least more tightly
>> grouped together.
>
> Between HDMI and DP adaptation differences are there but very minimal.
> Message avialbility check is completely different between HDMI and DP. DP
> uses the cp_irq.
> And timeout also varies for a DP HDCP msg.
>
> Since we are adapting the HDCP1.4 design where all encoder specific
> operations are pushed into hdcp_shim,
> I have implemented all HDMI and DP related operation to their respective
> shims.
> So that we need not do more if(dp/hdmi) in common code intel_hdcp.c atleast.
>
> The first design I had shared using the drm helper functions, dont have
> different flows for HDMI and DP.
> Where ever different treatment is required based on the adaptation, that was
> taken care then and there.
I'm not against having dp/hdmi specific functions, I'm against having
to spread that specific stuff all around in different places. If you
need msgid specific timeouts between DP and HDMI then maybe stuff them
into the lookup table, but from a quick look it seemed like that's not
the case.
And if the hdcp1.4 shim design is getting in the way, we need to fix
that. The hdcp1.4 shim is indeed a bit looking like a midlayer, so it
getting in the way is no surprise really.
-Daniel
>
> -Ram
>
>
>> Remapping from the HDCP_2_2 defines to the dpcd offsets is imo different
>> than all the stuff below here.
>> -Daniel
>>
>>> +{
>>> + int timeout;
>>> +
>>> + switch (msg_id) {
>>> + case HDCP_2_2_AKE_SEND_CERT:
>>> + timeout = HDCP_2_2_CERT_TIMEOUT;
>>> + break;
>>> + case HDCP_2_2_AKE_SEND_HPRIME:
>>> + if (paired)
>>> + timeout = HDCP_2_2_HPRIME_PAIRED_TIMEOUT;
>>> + else
>>> + timeout = HDCP_2_2_HPRIME_NO_PAIRED_TIMEOUT;
>>> + break;
>>> + case HDCP_2_2_AKE_SEND_PAIRING_INFO:
>>> + timeout = HDCP_2_2_PAIRING_TIMEOUT;
>>> + break;
>>> + case HDCP_2_2_LC_SEND_LPRIME:
>>> + timeout = HDCP_2_2_DP_LPRIME_TIMEOUT;
>>> + break;
>>> + case HDCP_2_2_REP_SEND_RECVID_LIST:
>>> + timeout = HDCP_2_2_RECVID_LIST_TIMEOUT;
>>> + break;
>>> + case HDCP_2_2_REP_STREAM_READY:
>>> + timeout = HDCP_2_2_STREAM_READY_TIMEOUT;
>>> + break;
>>> + default:
>>> + timeout = -EINVAL;
>>> + DRM_ERROR("Unsupported msg_id: %d\n", (int)msg_id);
>>> + }
>>> +
>>> + return timeout;
>>> +}
>>> +
>>> +static
>>> +int hdcp2_detect_msg_availability(struct intel_digital_port
>>> *intel_dig_port,
>>> + uint8_t msg_id, bool *msg_ready)
>>> +{
>>> + uint8_t rx_status;
>>> + int ret;
>>> +
>>> + *msg_ready = false;
>>> + ret = intel_dp_hdcp2_read_rx_status(intel_dig_port, &rx_status);
>>> + if (ret < 0)
>>> + return ret;
>>> +
>>> + switch (msg_id) {
>>> + case HDCP_2_2_AKE_SEND_HPRIME:
>>> + if (HDCP_2_2_DP_RXSTATUS_H_PRIME(rx_status))
>>> + *msg_ready = true;
>>> + break;
>>> + case HDCP_2_2_AKE_SEND_PAIRING_INFO:
>>> + if (HDCP_2_2_DP_RXSTATUS_PAIRING(rx_status))
>>> + *msg_ready = true;
>>> + break;
>>> + case HDCP_2_2_REP_SEND_RECVID_LIST:
>>> + if (HDCP_2_2_DP_RXSTATUS_READY(rx_status))
>>> + *msg_ready = true;
>>> + break;
>>> + default:
>>> + DRM_DEBUG_KMS("Unidentified msg_id: %d\n", (int)msg_id);
>>> + return -EINVAL;
>>> + }
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +
>>> +static ssize_t
>>> +intel_dp_hdcp2_wait_for_msg(struct intel_digital_port *intel_dig_port,
>>> + uint8_t msg_id)
>>> +{
>>> + struct intel_dp *dp = &intel_dig_port->dp;
>>> + struct intel_hdcp *hdcp = &dp->attached_connector->hdcp;
>>> + int ret, timeout;
>>> + bool msg_ready = false;
>>> +
>>> + timeout = intel_dp_hdcp2_timeout_for_msg(msg_id,
>>> hdcp->is_paired);
>>> + switch (msg_id) {
>>> +
>>> + /*
>>> + * There is no way to detect the CERT, LPRIME and STREAM_READY
>>> + * availability. So Wait for timeout and read the msg.
>>> + */
>>> + case HDCP_2_2_AKE_SEND_CERT:
>>> + case HDCP_2_2_LC_SEND_LPRIME:
>>> + case HDCP_2_2_REP_STREAM_READY:
>>> + mdelay(timeout);
>>> + ret = 0;
>>> + break;
>>> + case HDCP_2_2_AKE_SEND_HPRIME:
>>> + case HDCP_2_2_AKE_SEND_PAIRING_INFO:
>>> + case HDCP_2_2_REP_SEND_RECVID_LIST:
>>> + intel_dp_hdcp_wait_for_cp_irq(hdcp, timeout);
>>> + ret = hdcp2_detect_msg_availability(intel_dig_port,
>>> msg_id,
>>> + &msg_ready);
>>> + if (!msg_ready)
>>> + ret = -ETIMEDOUT;
>>> + break;
>>> + default:
>>> + DRM_DEBUG_KMS("Unidentified msg_id: %d\n", (int)msg_id);
>>> + return -EINVAL;
>>> + }
>>> + if (ret)
>>> + DRM_ERROR("msg_id %d, ret %d, timeout(mSec): %d\n",
>>> msg_id, ret,
>>> + timeout);
>>> +
>>> + return ret;
>>> +}
>>> +
>>> +static
>>> +int intel_dp_hdcp2_write_msg(struct intel_digital_port *intel_dig_port,
>>> + void *buf, size_t size)
>>> +{
>>> + unsigned int offset;
>>> + uint8_t *byte = buf;
>>> + ssize_t ret, bytes_to_write, len;
>>> +
>>> + if (intel_dpcd_offset_for_hdcp2_msgid(*byte, &offset) < 0)
>>> + return -EINVAL;
>>> +
>>> + /* No msg_id in DP HDCP2.2 msgs */
>>> + bytes_to_write = size - 1;
>>> + byte++;
>>> +
>>> + while (bytes_to_write) {
>>> + len = bytes_to_write > DP_AUX_MAX_PAYLOAD_BYTES ?
>>> + DP_AUX_MAX_PAYLOAD_BYTES :
>>> bytes_to_write;
>>> +
>>> + ret = drm_dp_dpcd_write(&intel_dig_port->dp.aux, offset,
>>> + (void *)byte, len);
>>> + if (ret < 0)
>>> + return ret;
>>> +
>>> + bytes_to_write -= ret;
>>> + byte += ret;
>>> + offset += ret;
>>> + }
>>> +
>>> + return size;
>>> +}
>>> +
>>> +static
>>> +int intel_dp_hdcp2_read_msg(struct intel_digital_port *intel_dig_port,
>>> + uint8_t msg_id, void *buf, size_t size)
>>> +{
>>> + unsigned int offset, dev_cnt;
>>> + uint8_t *byte = buf;
>>> + uint8_t rx_info[HDCP_2_2_RXINFO_LEN];
>>> + ssize_t ret, bytes_to_recv, len;
>>> +
>>> + if (intel_dpcd_offset_for_hdcp2_msgid(msg_id, &offset) < 0)
>>> + return -EINVAL;
>>> +
>>> + ret = intel_dp_hdcp2_wait_for_msg(intel_dig_port, msg_id);
>>> + if (ret < 0)
>>> + return ret;
>>> +
>>> + /* Finding the ReceiverID List size */
>>> + if (msg_id == HDCP_2_2_REP_SEND_RECVID_LIST) {
>>> + ret = drm_dp_dpcd_read(&intel_dig_port->dp.aux,
>>> + DP_HDCP_2_2_REG_RXINFO_OFFSET,
>>> + (void *)rx_info,
>>> HDCP_2_2_RXINFO_LEN);
>>> + if (ret != HDCP_2_2_RXINFO_LEN)
>>> + return ret >= 0 ? -EIO : ret;
>>> +
>>> + dev_cnt = (HDCP_2_2_DEV_COUNT_HI(rx_info[0]) << 4 |
>>> + HDCP_2_2_DEV_COUNT_LO(rx_info[1]));
>>> +
>>> + if (dev_cnt > HDCP_2_2_MAX_DEVICE_COUNT)
>>> + dev_cnt = HDCP_2_2_MAX_DEVICE_COUNT;
>>> +
>>> + size = sizeof(struct hdcp2_rep_send_receiverid_list) -
>>> + HDCP_2_2_RECEIVER_IDS_MAX_LEN +
>>> + (dev_cnt * HDCP_2_2_RECEIVER_ID_LEN);
>>> + }
>>> +
>>> + bytes_to_recv = size - 1;
>>> +
>>> + /* To skip the msg_id, as msgs in DP adaptation has no msg_id */
>>> + byte++;
>>> +
>>> + while (bytes_to_recv) {
>>> + len = bytes_to_recv > DP_AUX_MAX_PAYLOAD_BYTES ?
>>> + DP_AUX_MAX_PAYLOAD_BYTES : bytes_to_recv;
>>> +
>>> + ret = drm_dp_dpcd_read(&intel_dig_port->dp.aux, offset,
>>> + (void *)byte, len);
>>> + if (ret < 0) {
>>> + DRM_DEBUG_KMS("msg_id %d, ret %d\n", msg_id,
>>> (int)ret);
>>> + return ret;
>>> + }
>>> +
>>> + bytes_to_recv -= ret;
>>> + byte += ret;
>>> + offset += ret;
>>> + }
>>> + byte = buf;
>>> + *byte = msg_id;
>>> +
>>> + return size;
>>> +}
>>> +
>>> +static
>>> +int intel_dp_hdcp2_config_stream_type(struct intel_digital_port
>>> *intel_dig_port,
>>> + void *buf, size_t size)
>>> +{
>>> + return intel_dp_hdcp2_write_msg(intel_dig_port, buf, size);
>>> +}
>>> +
>>> +static
>>> +int intel_dp_hdcp2_check_link(struct intel_digital_port *intel_dig_port)
>>> +{
>>> + uint8_t rx_status;
>>> + int ret;
>>> +
>>> + ret = intel_dp_hdcp2_read_rx_status(intel_dig_port, &rx_status);
>>> + if (ret)
>>> + return ret;
>>> +
>>> + if (HDCP_2_2_DP_RXSTATUS_REAUTH_REQ(rx_status))
>>> + ret = DRM_HDCP_REAUTH_REQUEST;
>>> + else if (HDCP_2_2_DP_RXSTATUS_LINK_FAILED(rx_status))
>>> + ret = DRM_HDCP_LINK_INTEGRITY_FAILURE;
>>> + else if (HDCP_2_2_DP_RXSTATUS_READY(rx_status))
>>> + ret = DRM_HDCP_TOPOLOGY_CHANGE;
>>> +
>>> + return ret;
>>> +}
>>> +
>>> +static
>>> +int intel_dp_hdcp2_capable(struct intel_digital_port *intel_dig_port,
>>> + bool *capable)
>>> +{
>>> + uint8_t rx_caps[3];
>>> + int ret;
>>> +
>>> + *capable = false;
>>> + ret = drm_dp_dpcd_read(&intel_dig_port->dp.aux,
>>> + DP_HDCP_2_2_REG_RX_CAPS_OFFSET,
>>> + rx_caps, HDCP_2_2_RXCAPS_LEN);
>>> + if (ret != HDCP_2_2_RXCAPS_LEN)
>>> + return ret >= 0 ? -EIO : ret;
>>> +
>>> + if (rx_caps[0] == HDCP_2_2_RXCAPS_VERSION_VAL &&
>>> + HDCP_2_2_DP_HDCP_CAPABLE(rx_caps[2]))
>>> + *capable = true;
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static
>>> +enum hdcp_protocol intel_dp_hdcp2_protocol(void)
>>> +{
>>> + return HDCP_PROTOCOL_DP;
>>> +}
>>> +
>>> static const struct intel_hdcp_shim intel_dp_hdcp_shim = {
>>> .write_an_aksv = intel_dp_hdcp_write_an_aksv,
>>> .read_bksv = intel_dp_hdcp_read_bksv,
>>> @@ -5287,6 +5639,12 @@ static const struct intel_hdcp_shim
>>> intel_dp_hdcp_shim = {
>>> .toggle_signalling = intel_dp_hdcp_toggle_signalling,
>>> .check_link = intel_dp_hdcp_check_link,
>>> .hdcp_capable = intel_dp_hdcp_capable,
>>> + .write_2_2_msg = intel_dp_hdcp2_write_msg,
>>> + .read_2_2_msg = intel_dp_hdcp2_read_msg,
>>> + .config_stream_type = intel_dp_hdcp2_config_stream_type,
>>> + .check_2_2_link = intel_dp_hdcp2_check_link,
>>> + .hdcp_2_2_capable = intel_dp_hdcp2_capable,
>>> + .hdcp_protocol = intel_dp_hdcp2_protocol,
>>> };
>>> static void intel_edp_panel_vdd_sanitize(struct intel_dp *intel_dp)
>>> diff --git a/drivers/gpu/drm/i915/intel_drv.h
>>> b/drivers/gpu/drm/i915/intel_drv.h
>>> index def8e3255742..0496ebec287b 100644
>>> --- a/drivers/gpu/drm/i915/intel_drv.h
>>> +++ b/drivers/gpu/drm/i915/intel_drv.h
>>> @@ -444,6 +444,13 @@ struct intel_hdcp {
>>> struct mei_hdcp_data mei_data;
>>> struct notifier_block mei_cldev_nb;
>>> struct delayed_work hdcp2_check_work;
>>> +
>>> + /*
>>> + * Work queue to signal the CP_IRQ. Used for the waiters to read
>>> the
>>> + * available information from HDCP DP sink.
>>> + */
>>> + wait_queue_head_t cp_irq_queue;
>>> + atomic_t cp_irq_recved;
>>> };
>>> struct intel_connector {
>>> diff --git a/drivers/gpu/drm/i915/intel_hdcp.c
>>> b/drivers/gpu/drm/i915/intel_hdcp.c
>>> index d060d7f2e13b..d502bdb380d2 100644
>>> --- a/drivers/gpu/drm/i915/intel_hdcp.c
>>> +++ b/drivers/gpu/drm/i915/intel_hdcp.c
>>> @@ -870,6 +870,8 @@ int intel_hdcp_init(struct intel_connector
>>> *connector,
>>> if (hdcp2_supported)
>>> intel_hdcp2_init(connector);
>>> + init_waitqueue_head(&hdcp->cp_irq_queue);
>>> + atomic_set(&hdcp->cp_irq_recved, 0);
>>> return 0;
>>> }
>>> @@ -1849,4 +1851,7 @@ void intel_hdcp_handle_cp_irq(struct
>>> intel_connector *connector)
>>> intel_hdcp_check_link(connector);
>>> else if (intel_hdcp2_in_force(connector))
>>> intel_hdcp2_check_link(connector);
>>> +
>>> + atomic_set(&connector->hdcp.cp_irq_recved, 1);
>>> + wake_up_all(&connector->hdcp.cp_irq_queue);
>>> }
>>> --
>>> 2.7.4
>>>
>
--
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch
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