On 11/24/21 2:40 PM, Badhri Jagan Sridharan wrote:
Stub from the spec: "4.5.2.2.4.2 Exiting from AttachWait.SNK State A Sink shall transition to Unattached.SNK when the state of both the CC1 and CC2 pins is SNK.Open for at least tPDDebounce. A DRP shall transition to Unattached.SRC when the state of both the CC1 and CC2 pins is SNK.Open for at least tPDDebounce."
This change makes TCPM to wait in SNK_DEBOUNCED state until CC1 and CC2 pins is SNK.Open for at least tPDDebounce. Previously, TCPM resets the port if vbus is not present in PD_T_PS_SOURCE_ON. This causes TCPM to loop continuously when connected to a faulty power source that does not present vbus. Waiting in SNK_DEBOUNCED also ensures that TCPM is adherant to "4.5.2.2.4.2 Exiting from AttachWait.SNK State" requirements.
[ 6169.280751] CC1: 0 -> 0, CC2: 0 -> 5 [state TOGGLING, polarity 0, connected] [ 6169.280759] state change TOGGLING -> SNK_ATTACH_WAIT [rev2 NONE_AMS] [ 6169.280771] pending state change SNK_ATTACH_WAIT -> SNK_DEBOUNCED @ 170 ms [rev2 NONE_AMS] [ 6169.282427] CC1: 0 -> 0, CC2: 5 -> 5 [state SNK_ATTACH_WAIT, polarity 0, connected] [ 6169.450825] state change SNK_ATTACH_WAIT -> SNK_DEBOUNCED [delayed 170 ms] [ 6169.450834] pending state change SNK_DEBOUNCED -> PORT_RESET @ 480 ms [rev2 NONE_AMS] [ 6169.930892] state change SNK_DEBOUNCED -> PORT_RESET [delayed 480 ms] [ 6169.931296] disable vbus discharge ret:0 [ 6169.931301] Setting usb_comm capable false [ 6169.932783] Setting voltage/current limit 0 mV 0 mA [ 6169.932802] polarity 0 [ 6169.933706] Requesting mux state 0, usb-role 0, orientation 0 [ 6169.936689] cc:=0 [ 6169.936812] pending state change PORT_RESET -> PORT_RESET_WAIT_OFF @ 100 ms [rev2 NONE_AMS] [ 6169.937157] CC1: 0 -> 0, CC2: 5 -> 0 [state PORT_RESET, polarity 0, disconnected] [ 6170.036880] state change PORT_RESET -> PORT_RESET_WAIT_OFF [delayed 100 ms] [ 6170.036890] state change PORT_RESET_WAIT_OFF -> SNK_UNATTACHED [rev2 NONE_AMS] [ 6170.036896] Start toggling [ 6170.041412] CC1: 0 -> 0, CC2: 0 -> 0 [state TOGGLING, polarity 0, disconnected] [ 6170.042973] CC1: 0 -> 0, CC2: 0 -> 5 [state TOGGLING, polarity 0, connected] [ 6170.042976] state change TOGGLING -> SNK_ATTACH_WAIT [rev2 NONE_AMS] [ 6170.042981] pending state change SNK_ATTACH_WAIT -> SNK_DEBOUNCED @ 170 ms [rev2 NONE_AMS] [ 6170.213014] state change SNK_ATTACH_WAIT -> SNK_DEBOUNCED [delayed 170 ms] [ 6170.213019] pending state change SNK_DEBOUNCED -> PORT_RESET @ 480 ms [rev2 NONE_AMS] [ 6170.693068] state change SNK_DEBOUNCED -> PORT_RESET [delayed 480 ms] [ 6170.693304] disable vbus discharge ret:0 [ 6170.693308] Setting usb_comm capable false [ 6170.695193] Setting voltage/current limit 0 mV 0 mA [ 6170.695210] polarity 0 [ 6170.695990] Requesting mux state 0, usb-role 0, orientation 0 [ 6170.701896] cc:=0 [ 6170.702181] pending state change PORT_RESET -> PORT_RESET_WAIT_OFF @ 100 ms [rev2 NONE_AMS] [ 6170.703343] CC1: 0 -> 0, CC2: 5 -> 0 [state PORT_RESET, polarity 0, disconnected]
Fixes: f0690a25a140b8 ("staging: typec: USB Type-C Port Manager (tcpm)") Signed-off-by: Badhri Jagan Sridharan badhri@google.com
Reviewed-by: Guenter Roeck linux@roeck-us.net
drivers/usb/typec/tcpm/tcpm.c | 4 ---- 1 file changed, 4 deletions(-)
diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c index 7f2f3ff1b391..6010b9901126 100644 --- a/drivers/usb/typec/tcpm/tcpm.c +++ b/drivers/usb/typec/tcpm/tcpm.c @@ -4110,11 +4110,7 @@ static void run_state_machine(struct tcpm_port *port) tcpm_try_src(port) ? SRC_TRY : SNK_ATTACHED, 0);
else/* Wait for VBUS, but not forever */tcpm_set_state(port, PORT_RESET, PD_T_PS_SOURCE_ON);- case SRC_TRY: port->try_src_count++; tcpm_set_cc(port, tcpm_rp_cc(port));