[PATCH 1/1] usb: typec: tcpm: PSSourceOffTimer timeout in PR_Swap enters ERROR_RECOVERY

From: joswang
Date: Sun Feb 09 2025 - 02:18:14 EST


From: Jos Wang <joswang@xxxxxxxxxx>

As PD2.0 spec ("6.5.6.2 PSSourceOffTimer"),the PSSourceOffTimer is
used by the Policy Engine in Dual-Role Power device that is currently
acting as a Sink to timeout on a PS_RDY Message during a Power Role
Swap sequence. This condition leads to a Hard Reset for USB Type-A and
Type-B Plugs and Error Recovery for Type-C plugs and return to USB
Default Operation.

Therefore, after PSSourceOffTimer timeout, the tcpm state machine should
switch from PR_SWAP_SNK_SRC_SINK_OFF to ERROR_RECOVERY. This can also solve
the test items in the USB power delivery compliance test:
TEST.PD.PROT.SNK.12 PR_Swap – PSSourceOffTimer Timeout

[1] https://usb.org/document-library/usb-power-delivery-compliance-test-specification-0/USB_PD3_CTS_Q4_2025_OR.zip

Fixes: f0690a25a140 ("staging: typec: USB Type-C Port Manager (tcpm)")
Cc: stable@xxxxxxxxxxxxxxx

Signed-off-by: Jos Wang <joswang@xxxxxxxxxx>
---
drivers/usb/typec/tcpm/tcpm.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
index 47be450d2be3..6bf1a22c785a 100644
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -5591,8 +5591,7 @@ static void run_state_machine(struct tcpm_port *port)
tcpm_set_auto_vbus_discharge_threshold(port, TYPEC_PWR_MODE_USB,
port->pps_data.active, 0);
tcpm_set_charge(port, false);
- tcpm_set_state(port, hard_reset_state(port),
- port->timings.ps_src_off_time);
+ tcpm_set_state(port, ERROR_RECOVERY, port->timings.ps_src_off_time);
break;
case PR_SWAP_SNK_SRC_SOURCE_ON:
tcpm_enable_auto_vbus_discharge(port, true);
--
2.17.1