[PATCH 08/11] staging: typec: tcpm: add cc change handling in src states

[Badhri Jagan Sridharan <badhri@google.com>]

In the case that the lower layer driver reports a cc change directly
from SINK state to SOURCE state, TCPM doesn't handle these cc change
in SRC_SEND_CAPABILITIES, SRC_READY states. And with SRC_ATTACHED
state, the change is not handled as the port is still considered
connected.

[49606.131672] state change DRP_TOGGLING -> SRC_ATTACH_WAIT
[49606.131701] pending state change SRC_ATTACH_WAIT -> SRC_ATTACHED @
200 ms
[49606.329952] state change SRC_ATTACH_WAIT -> SRC_ATTACHED [delayed 200
ms]
[49606.329978] polarity 0
[49606.329989] Requesting mux mode 1, config 0, polarity 0
[49606.349416] vbus:=1 charge=0
[49606.372274] pending state change SRC_ATTACHED -> SRC_UNATTACHED @ 480
ms
[49606.372431] VBUS on
[49606.372488] state change SRC_ATTACHED -> SRC_STARTUP
...
(the lower layer driver reports a direct change from source to sink)
[49606.536927] pending state change SRC_SEND_CAPABILITIES ->
SRC_SEND_CAPABILITIES @ 150 ms
[49606.547244] CC1: 2 -> 5, CC2: 0 -> 0 [state SRC_SEND_CAPABILITIES,
polarity 0, connected]

This can happen when the lower layer driver and/or the hardware
handles a portion of the Type-C state machine work, and quietly goes
through the unattached state.

Originally-from: Yueyao Zhu <yueyao@google.com>
Signed-off-by: Badhri Jagan Sridharan <Badhri@google.com>
---
 drivers/staging/typec/tcpm.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/typec/tcpm.c b/drivers/staging/typec/tcpm.c
index 645f43ee83df..1f6827f32b29 100644
--- a/drivers/staging/typec/tcpm.c
+++ b/drivers/staging/typec/tcpm.c
@@ -2874,10 +2874,12 @@ static void _tcpm_cc_change(struct tcpm_port *port, enum typec_cc_status cc1,
 			tcpm_set_state(port, SRC_ATTACH_WAIT, 0);
 		break;
 	case SRC_ATTACHED:
-		if (tcpm_port_is_disconnected(port))
+	case SRC_SEND_CAPABILITIES:
+	case SRC_READY:
+		if (tcpm_port_is_disconnected(port) ||
+		    !tcpm_port_is_source(port))
 			tcpm_set_state(port, SRC_UNATTACHED, 0);
 		break;
-
 	case SNK_UNATTACHED:
 		if (tcpm_port_is_sink(port))
 			tcpm_set_state(port, SNK_ATTACH_WAIT, 0);
-- 
2.14.1.342.g6490525c54-goog