[PATCH 5.12 020/677] usb: typec: tcpm: Address incorrect values of tcpm psy for fixed supply

From: Greg Kroah-Hartman
Date: Wed May 12 2021 - 14:06:05 EST


From: Badhri Jagan Sridharan <badhri@xxxxxxxxxx>

commit f3dedafb8263ca4791a92a23f5230068f5bde008 upstream.

tcpm_pd_build_request overwrites current_limit and supply_voltage
even before port partner accepts the requests. This leaves stale
values in current_limit and supply_voltage that get exported by
"tcpm-source-psy-". Solving this problem by caching the request
values of current limit/supply voltage in req_current_limit
and req_supply_voltage. current_limit/supply_voltage gets updated
once the port partner accepts the request.

Fixes: f2a8aa053c176 ("typec: tcpm: Represent source supply through power_supply")
Signed-off-by: Badhri Jagan Sridharan <badhri@xxxxxxxxxx>
Cc: stable <stable@xxxxxxxxxxxxxxx>
Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Reviewed-by: Adam Thomson <Adam.Thomson.Opensource@xxxxxxxxxxx>
Reviewed-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20210407200723.1914388-1-badhri@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/usb/typec/tcpm/tcpm.c | 17 ++++++++++-------
1 file changed, 10 insertions(+), 7 deletions(-)

--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -389,7 +389,10 @@ struct tcpm_port {
unsigned int operating_snk_mw;
bool update_sink_caps;

- /* Requested current / voltage */
+ /* Requested current / voltage to the port partner */
+ u32 req_current_limit;
+ u32 req_supply_voltage;
+ /* Actual current / voltage limit of the local port */
u32 current_limit;
u32 supply_voltage;

@@ -2432,8 +2435,8 @@ static void tcpm_pd_ctrl_request(struct
case SNK_TRANSITION_SINK:
if (port->vbus_present) {
tcpm_set_current_limit(port,
- port->current_limit,
- port->supply_voltage);
+ port->req_current_limit,
+ port->req_supply_voltage);
port->explicit_contract = true;
tcpm_set_auto_vbus_discharge_threshold(port,
TYPEC_PWR_MODE_PD,
@@ -2542,8 +2545,8 @@ static void tcpm_pd_ctrl_request(struct
break;
case SNK_NEGOTIATE_PPS_CAPABILITIES:
port->pps_data.active = true;
- port->supply_voltage = port->pps_data.out_volt;
- port->current_limit = port->pps_data.op_curr;
+ port->req_supply_voltage = port->pps_data.out_volt;
+ port->req_current_limit = port->pps_data.op_curr;
tcpm_set_state(port, SNK_TRANSITION_SINK, 0);
break;
case SOFT_RESET_SEND:
@@ -3192,8 +3195,8 @@ static int tcpm_pd_build_request(struct
flags & RDO_CAP_MISMATCH ? " [mismatch]" : "");
}

- port->current_limit = ma;
- port->supply_voltage = mv;
+ port->req_current_limit = ma;
+ port->req_supply_voltage = mv;

return 0;
}