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usb: typec: tcpm: constrain TCPM_SOURCING_VBUS event handling

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When a sink detach occurs while waiting for TX send status, the old
TCPM_SOURCING_VBUS event along with TCPM_VBUS_EVENT and TCPM_CC_EVENT
can be queued in port->pd_events. Because TCPM_SOURCING_VBUS is
evaluated after TCPM_VBUS_EVENT and TCPM_CC_EVENT in
tcpm_pd_event_handler(), a stale TCPM_SOURCING_VBUS event can override
the detach handling and incorrectly set port->vbus_source and
port->vbus_present to true.

Add a state guard to check that the port is either operating as a
Source (tcpm_port_is_source(port)) or in a Fast Role Swap (FRS) state
up to FR_SWAP_SNK_SRC_SOURCE_VBUS_APPLIED before processing
TCPM_SOURCING_VBUS. Otherwise, discard and log the event.

Log snippet for error condition before fix:
[72792.204955] state change SRC_ATTACHED -> SRC_STARTUP [rev3 NONE_AMS]
[72792.204960] sourcing vbus
[72792.204962] VBUS on
[72792.204970] AMS POWER_NEGOTIATION start
[72792.204974] cc:=4
[72792.205319] state change SRC_STARTUP -> AMS_START [rev3 POWER_NEGOTIATION]
[72792.205325] state change AMS_START -> SRC_SEND_CAPABILITIES [rev3 POWER_NEGOTIATION]
[72792.205332] PD TX, header: 0x11a1
[72792.216911] PD TX complete, status: 2
[72792.216957] pending state change SRC_SEND_CAPABILITIES -> SRC_SEND_CAPABILITIES @ 150 ms [rev3 POWER_NEGOTIATION]
[72792.218005] VBUS off
[72792.218013] pending state change SRC_SEND_CAPABILITIES -> SNK_UNATTACHED @ 650 ms [rev3 POWER_NEGOTIATION]
[72792.218020] VBUS VSAFE0V
[72792.218024] state change SRC_SEND_CAPABILITIES -> SNK_UNATTACHED [rev3 POWER_NEGOTIATION]
[72792.218458] CC1: 2 -> 0, CC2: 0 -> 0 [state SNK_UNATTACHED, polarity 0, disconnected]
[72792.218467] VBUS on --> VBUS left on
[72792.218980] disable vbus discharge ret:0
[72792.235193] Start toggling

After fix:
[ 1195.291691] state change SRC_ATTACHED -> SRC_STARTUP [rev3 NONE_AMS]
[ 1195.291698] sourcing vbus
[ 1195.291700] VBUS on
[ 1195.291707] AMS POWER_NEGOTIATION start
[ 1195.291710] cc:=4
[ 1195.291758] state change SRC_STARTUP -> AMS_START [rev3 POWER_NEGOTIATION]
[ 1195.291794] state change AMS_START -> SRC_SEND_CAPABILITIES [rev3 POWER_NEGOTIATION]
[ 1195.291798] PD TX, header: 0x11a1
[ 1195.297056] PD TX complete, status: 2
[ 1195.297092] pending state change SRC_SEND_CAPABILITIES -> SRC_SEND_CAPABILITIES @ 150 ms [rev3 POWER_NEGOTIATION]
[ 1195.297177] VBUS off
[ 1195.297184] pending state change SRC_SEND_CAPABILITIES -> SNK_UNATTACHED @ 650 ms [rev3 POWER_NEGOTIATION]
[ 1195.297227] CC1: 2 -> 0, CC2: 0 -> 0 [state SRC_SEND_CAPABILITIES, polarity 0, disconnected]
[ 1195.307469] cc:=2
[ 1195.307544] pending state change SRC_SEND_CAPABILITIES -> SNK_UNATTACHED @ 650 ms [rev3 POWER_NEGOTIATION]
[ 1195.307555] Discarding sourcing vbus! Invalid state SRC_SEND_CAPABILITIES
[ 1195.957636] state change SRC_SEND_CAPABILITIES -> SNK_UNATTACHED [delayed 650 ms]
[ 1195.957732] disable vbus discharge ret:0
[ 1195.970196] Start toggling
[ 1195.970468] VBUS off
[ 1196.051637] VBUS off
[ 1196.051642] VBUS VSAFE0V

Fixes: 8dc4bd0736 ("usb: typec: tcpm: Add support for Sink Fast Role SWAP(FRS)")
Cc: stable <stable@kernel.org>
Assisted-by: Gemini:gemini-3.1-pro
Signed-off-by: Amit Sunil Dhamne <amitsd@google.com>
Reviewed-by: Badhri Jagan Sridharan <badhri@google.com>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://patch.msgid.link/20260827-sourcing-vbus-v1-1-9be1aca991a0@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Amit Sunil Dhamne 2026-08-27 21:16:17 +00:00 committed by Greg Kroah-Hartman
parent 04cec690b1
commit cd3b9cea67
1 changed files with 22 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

28
drivers/usb/typec/tcpm/tcpm.c
View File

@ -7119,16 +7119,32 @@ static void tcpm_pd_event_handler(struct kthread_work *work)
}
}
if (events & TCPM_SOURCING_VBUS) {
tcpm_log(port, "sourcing vbus");
/*
* In fast role swap case TCPC autonomously sources vbus. Set vbus_source
* true as TCPM wouldn't have called tcpm_set_vbus.
* true conditionally as TCPM wouldn't have called tcpm_set_vbus.
* If TCPM calls tcpm_set_vbus to source vbus, vbus_source would already
* be true.
*
* When vbus is sourced on the command on TCPM i.e. TCPM called
* tcpm_set_vbus to source vbus, vbus_source would already be true.
* When TCPM_FRS_EVENT and TCPM_SOURCING_VBUS arrive simultaneously,
* handling TCPM_FRS_EVENT above transitions the state to AMS_START
* with upcoming_state FR_SWAP_SEND.
*/
port->vbus_source = true;
_tcpm_pd_vbus_on(port);
if (tcpm_port_is_source(port) ||
tcpm_port_is_debug_source(port) ||
(port->state == AMS_START && port->upcoming_state == FR_SWAP_SEND) ||
port->state == FR_SWAP_SEND ||
port->state == FR_SWAP_SEND_TIMEOUT ||
port->state == FR_SWAP_SNK_SRC_TRANSITION_TO_OFF ||
port->state == FR_SWAP_SNK_SRC_NEW_SINK_READY ||
port->state == FR_SWAP_SNK_SRC_SOURCE_VBUS_APPLIED) {
tcpm_log(port, "sourcing vbus");
port->vbus_source = true;
_tcpm_pd_vbus_on(port);
} else {
tcpm_log(port, "Discarding sourcing vbus! Invalid state %s",
tcpm_states[port->state]);
}
}
if (events & TCPM_PORT_CLEAN) {
tcpm_log(port, "port clean");