[PATCH 4/5] USB: typec: tcpm: Add a 30ms room for tPSSourceOn in PR_SWAP

From: Greg Kroah-Hartman
Date: Thu Dec 10 2020 - 11:25:42 EST


From: Kyle Tso <kyletso@xxxxxxxxxx>

TCPM state machine needs 20-25ms to enter the ErrorRecovery state after
tPSSourceOn timer timeouts. Change the timer from max 480ms to 450ms to
ensure that the timer complies with the Spec. In order to keep the
flexibility for other usecases using tPSSourceOn, add another timer only
for PR_SWAP.

Cc: Guenter Roeck <linux@xxxxxxxxxxxx>
Cc: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
Cc: Badhri Jagan Sridharan <badhri@xxxxxxxxxx>
Signed-off-by: Kyle Tso <kyletso@xxxxxxxxxx>
Signed-off-by: Will McVicker <willmcvicker@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/usb/typec/tcpm/tcpm.c | 2 +-
include/linux/usb/pd.h | 1 +
2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
index d51c45961893..5ed78194a1bd 100644
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -3728,7 +3728,7 @@ static void run_state_machine(struct tcpm_port *port)
tcpm_set_state(port, ERROR_RECOVERY, 0);
break;
}
- tcpm_set_state(port, ERROR_RECOVERY, PD_T_PS_SOURCE_ON);
+ tcpm_set_state(port, ERROR_RECOVERY, PD_T_PS_SOURCE_ON_PRS);
break;
case PR_SWAP_SRC_SNK_SINK_ON:
/* Set the vbus disconnect threshold for implicit contract */
diff --git a/include/linux/usb/pd.h b/include/linux/usb/pd.h
index 63a66dd5d832..bb9a782e1411 100644
--- a/include/linux/usb/pd.h
+++ b/include/linux/usb/pd.h
@@ -466,6 +466,7 @@ static inline unsigned int rdo_max_power(u32 rdo)
#define PD_T_DRP_SRC 30
#define PD_T_PS_SOURCE_OFF 920
#define PD_T_PS_SOURCE_ON 480
+#define PD_T_PS_SOURCE_ON_PRS 450 /* 390 - 480ms */
#define PD_T_PS_HARD_RESET 30
#define PD_T_SRC_RECOVER 760
#define PD_T_SRC_RECOVER_MAX 1000
--
2.29.2