Revert "usb: typec: tcpm: clear pd_event queue in PORT_RESET"

This reverts commit bf20c69.

During tcpm_init() stage, if the VBUS is still present after
tcpm_reset_port(), then we assume that VBUS will off and goto safe0v
after a specific discharge time. Following a TCPM_VBUS_EVENT event if
VBUS reach to off state. TCPM_VBUS_EVENT event may be set during
PORT_RESET handling stage. If pd_events reset to 0 after TCPM_VBUS_EVENT
set, we will lost this VBUS event. Then the port state machine may stuck
at one state.

Before:

[    2.570172] pending state change PORT_RESET -> PORT_RESET_WAIT_OFF @ 100 ms [rev1 NONE_AMS]
[    2.570179] state change PORT_RESET -> PORT_RESET_WAIT_OFF [delayed 100 ms]
[    2.570182] pending state change PORT_RESET_WAIT_OFF -> SNK_UNATTACHED @ 920 ms [rev1 NONE_AMS]
[    3.490213] state change PORT_RESET_WAIT_OFF -> SNK_UNATTACHED [delayed 920 ms]
[    3.490220] Start toggling
[    3.546050] CC1: 0 -> 0, CC2: 0 -> 2 [state TOGGLING, polarity 0, connected]
[    3.546057] state change TOGGLING -> SRC_ATTACH_WAIT [rev1 NONE_AMS]

After revert this patch, we can see VBUS off event and the port will goto
expected state.

[    2.441992] pending state change PORT_RESET -> PORT_RESET_WAIT_OFF @ 100 ms [rev1 NONE_AMS]
[    2.441999] state change PORT_RESET -> PORT_RESET_WAIT_OFF [delayed 100 ms]
[    2.442002] pending state change PORT_RESET_WAIT_OFF -> SNK_UNATTACHED @ 920 ms [rev1 NONE_AMS]
[    2.442122] VBUS off
[    2.442125] state change PORT_RESET_WAIT_OFF -> SNK_UNATTACHED [rev1 NONE_AMS]
[    2.442127] VBUS VSAFE0V
[    2.442351] CC1: 0 -> 0, CC2: 0 -> 0 [state SNK_UNATTACHED, polarity 0, disconnected]
[    2.442357] Start toggling
[    2.491850] CC1: 0 -> 0, CC2: 0 -> 2 [state TOGGLING, polarity 0, connected]
[    2.491858] state change TOGGLING -> SRC_ATTACH_WAIT [rev1 NONE_AMS]
[    2.491863] pending state change SRC_ATTACH_WAIT -> SNK_TRY @ 200 ms [rev1 NONE_AMS]
[    2.691905] state change SRC_ATTACH_WAIT -> SNK_TRY [delayed 200 ms]

Fixes: bf20c69 ("usb: typec: tcpm: clear pd_event queue in PORT_RESET")
Cc: [email protected]
Signed-off-by: Xu Yang <[email protected]>
Acked-by: Heikki Krogerus <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: Xu Yang

drivers/usb/typec/tcpm/tcpm.c

@@ -5655,7 +5655,6 @@ static void run_state_machine(struct tcpm_port *port)
 		break;
 	case PORT_RESET:
 		tcpm_reset_port(port);
-		port->pd_events = 0;
 		if (port->self_powered)
 			tcpm_set_cc(port, TYPEC_CC_OPEN);
 		else