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| author | udaykiran <udaykiran@google.com> | 2021-06-18 23:07:05 -0700 |
|---|---|---|
| committer | Commit Bot <commit-bot@chromium.org> | 2021-06-25 03:33:38 +0000 |
| commit | 1e6577393086546f983d325be264293dbfc12a76 (patch) | |
| tree | 9facfe6c7bb34c8545fd75380de6f029315c8f00 /common/usbc/usb_pe_drp_sm.c | |
| parent | 07578aee1c0c64343ee0de7e186a708984552904 (diff) | |
| download | chrome-ec-1e6577393086546f983d325be264293dbfc12a76.tar.gz | |
SenderResponseTimer: offset with TCPC transmit success timestamp
The SenderResponseTimer shall be used by the sender's policy engine to
ensure that a message requesting a response is responded to within a
bounded time. Which is 24Msec to 30 Msec. However, delays associated
TCPC I2C, PE, and PRL layers make hard reset response time greater 30Msec.
This CL address the delay associated with TCPC. When TCPC transmit
success is reported by TCPC upon receiving the GoodCRC, time stamp is
recorded. Another time stamp is recorded just before starting
SenderResponseTimer and offsetting PD_T_SENDER_RESPONSE.
BUG=b:182439366
BRANCH=none
TEST=checked with GRL compliance tester. Noted that total response time
is in the middle of the expected time of 24ms to 30ms. This fix achieved
response time about 27.675ms
Signed-off-by: udaykiran <udaykiran@google.com>
Change-Id: Id2ddcdd90eed8b3d66ade3d16877004871a21de8
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2971078
Reviewed-by: Diana Z <dzigterman@chromium.org>
Diffstat (limited to 'common/usbc/usb_pe_drp_sm.c')
| -rw-r--r-- | common/usbc/usb_pe_drp_sm.c | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/common/usbc/usb_pe_drp_sm.c b/common/usbc/usb_pe_drp_sm.c index 9171b2fb94..e0a364240b 100644 --- a/common/usbc/usb_pe_drp_sm.c +++ b/common/usbc/usb_pe_drp_sm.c @@ -2016,6 +2016,8 @@ static void pe_sender_response_msg_entry(const int port) */ static enum pe_msg_check pe_sender_response_msg_run(const int port) { + timestamp_t tx_success_ts; + uint32_t offset; if (pd_timer_is_disabled(port, PE_TIMER_SENDER_RESPONSE)) { /* Check for Discard */ if (PE_CHK_FLAG(port, PE_FLAGS_MSG_DISCARDED)) { @@ -2034,9 +2036,19 @@ static enum pe_msg_check pe_sender_response_msg_run(const int port) if (PE_CHK_FLAG(port, PE_FLAGS_TX_COMPLETE)) { PE_CLR_FLAG(port, PE_FLAGS_TX_COMPLETE); - /* Initialize and run the SenderResponseTimer */ + /* TCPC TX success time stamp */ + tx_success_ts = prl_get_tcpc_tx_success_ts(port); + /* Calculate the delay from TX success to PE */ + offset = time_since32(tx_success_ts); + + /* + * Initialize and run the SenderResponseTimer by + * offsetting it with TX transmit success time. + * This would remove the effect of the latency from + * propagating the TX status. + */ pd_timer_enable(port, PE_TIMER_SENDER_RESPONSE, - PD_T_SENDER_RESPONSE); + PD_T_SENDER_RESPONSE - offset); return PE_MSG_SEND_COMPLETED; } return PE_MSG_SEND_PENDING; |