From: Kyle Tso Date: Wed, 16 Jun 2021 09:01:02 +0000 (+0800) Subject: usb: typec: tcpm: Relax disconnect threshold during power negotiation X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=2b537cf877eae6d2f2f102052290676e40b74a1d;p=linux.git usb: typec: tcpm: Relax disconnect threshold during power negotiation If the voltage is being decreased in power negotiation, the Source will set the power supply to operate at the new voltage level before sending PS_RDY. Relax the threshold before sending Request Message so that it will not race with Source which begins to adjust the voltage right after it sends Accept Message (PPS) or tSrcTransition (25~35ms) after it sends Accept Message (non-PPS). The real threshold will be set after Sink receives PS_RDY Message. Fixes: f321a02caebd ("usb: typec: tcpm: Implement enabling Auto Discharge disconnect support") Cc: stable Cc: Badhri Jagan Sridharan Reviewed-by: Badhri Jagan Sridharan Acked-by: Heikki Krogerus Signed-off-by: Kyle Tso Link: https://lore.kernel.org/r/20210616090102.1897674-1-kyletso@google.com Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c index e11e9227107dd..5b22a1c931a9e 100644 --- a/drivers/usb/typec/tcpm/tcpm.c +++ b/drivers/usb/typec/tcpm/tcpm.c @@ -2604,6 +2604,11 @@ static void tcpm_pd_ctrl_request(struct tcpm_port *port, } else { next_state = SNK_WAIT_CAPABILITIES; } + + /* Threshold was relaxed before sending Request. Restore it back. */ + tcpm_set_auto_vbus_discharge_threshold(port, TYPEC_PWR_MODE_PD, + port->pps_data.active, + port->supply_voltage); tcpm_set_state(port, next_state, 0); break; case SNK_NEGOTIATE_PPS_CAPABILITIES: @@ -2617,6 +2622,11 @@ static void tcpm_pd_ctrl_request(struct tcpm_port *port, port->send_discover) port->vdm_sm_running = true; + /* Threshold was relaxed before sending Request. Restore it back. */ + tcpm_set_auto_vbus_discharge_threshold(port, TYPEC_PWR_MODE_PD, + port->pps_data.active, + port->supply_voltage); + tcpm_set_state(port, SNK_READY, 0); break; case DR_SWAP_SEND: @@ -3336,6 +3346,12 @@ static int tcpm_pd_send_request(struct tcpm_port *port) if (ret < 0) return ret; + /* + * Relax the threshold as voltage will be adjusted after Accept Message plus tSrcTransition. + * It is safer to modify the threshold here. + */ + tcpm_set_auto_vbus_discharge_threshold(port, TYPEC_PWR_MODE_USB, false, 0); + memset(&msg, 0, sizeof(msg)); msg.header = PD_HEADER_LE(PD_DATA_REQUEST, port->pwr_role, @@ -3433,6 +3449,9 @@ static int tcpm_pd_send_pps_request(struct tcpm_port *port) if (ret < 0) return ret; + /* Relax the threshold as voltage will be adjusted right after Accept Message. */ + tcpm_set_auto_vbus_discharge_threshold(port, TYPEC_PWR_MODE_USB, false, 0); + memset(&msg, 0, sizeof(msg)); msg.header = PD_HEADER_LE(PD_DATA_REQUEST, port->pwr_role, @@ -4196,6 +4215,10 @@ static void run_state_machine(struct tcpm_port *port) port->hard_reset_count = 0; ret = tcpm_pd_send_request(port); if (ret < 0) { + /* Restore back to the original state */ + tcpm_set_auto_vbus_discharge_threshold(port, TYPEC_PWR_MODE_PD, + port->pps_data.active, + port->supply_voltage); /* Let the Source send capabilities again. */ tcpm_set_state(port, SNK_WAIT_CAPABILITIES, 0); } else { @@ -4206,6 +4229,10 @@ static void run_state_machine(struct tcpm_port *port) case SNK_NEGOTIATE_PPS_CAPABILITIES: ret = tcpm_pd_send_pps_request(port); if (ret < 0) { + /* Restore back to the original state */ + tcpm_set_auto_vbus_discharge_threshold(port, TYPEC_PWR_MODE_PD, + port->pps_data.active, + port->supply_voltage); port->pps_status = ret; /* * If this was called due to updates to sink