usb: typec: tcpm: Address incorrect values of tcpm psy for fixed supply

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@google.com>
Cc: stable <stable@vger.kernel.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Adam Thomson <Adam.Thomson.Opensource@diasemi.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20210407200723.1914388-1-badhri@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
index ca1fc77..4ea4b30 100644 (file)
--- 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;
 
@@ -2435,8 +2438,8 @@ static void tcpm_pd_ctrl_request(struct tcpm_port *port,
                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,
@@ -2545,8 +2548,8 @@ static void tcpm_pd_ctrl_request(struct tcpm_port *port,
                        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:
@@ -3195,8 +3198,8 @@ static int tcpm_pd_build_request(struct tcpm_port *port, u32 *rdo)
                         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;
 }