On Thu, Mar 18, 2021 at 8:26 AM Adam Thomson
[off-list ref] wrote:

On 17 March 2021 18:13, Badhri Jagan Sridharan wrote:

quoted

tcpm-source-psy- does not invoke power_supply_changed API when
one of the published power supply properties is changed.
power_supply_changed needs to be called to notify
userspace clients(uevents) and kernel clients.

Fixes: f2a8aa053c176("typec: tcpm: Represent source supply through
power_supply")
Signed-off-by: Badhri Jagan Sridharan <badhri@google.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
---
Changes since V1:
- Fixed commit message as per Guenter's suggestion
- Added Reviewed-by tags
- cc'ed stable
---
 drivers/usb/typec/tcpm/tcpm.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
index 11d0c40bc47d..e8936ea17f80 100644
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c

@@ -945,6 +945,7 @@ static int tcpm_set_current_limit(struct tcpm_port *port,

u32 max_ma, u32 mv)

      port->supply_voltage = mv;
      port->current_limit = max_ma;
+     power_supply_changed(port->psy);

      if (port->tcpc->set_current_limit)
              ret = port->tcpc->set_current_limit(port->tcpc, max_ma, mv);

@@ -2931,6 +2932,7 @@ static int tcpm_pd_select_pdo(struct tcpm_port *port,

int *sink_pdo,

      port->pps_data.supported = false;
      port->usb_type = POWER_SUPPLY_USB_TYPE_PD;
+     power_supply_changed(port->psy);

      /*
       * Select the source PDO providing the most power which has a

@@ -2955,6 +2957,7 @@ static int tcpm_pd_select_pdo(struct tcpm_port *port,

int *sink_pdo,
                              port->pps_data.supported = true;
                              port->usb_type =
                                      POWER_SUPPLY_USB_TYPE_PD_PPS;
+                             power_supply_changed(port->psy);
                      }
                      continue;
              default:

@@ -3112,6 +3115,7 @@ static unsigned int tcpm_pd_select_pps_apdo(struct

tcpm_port *port)
                                                port->pps_data.out_volt));
              port->pps_data.op_curr = min(port->pps_data.max_curr,
                                           port->pps_data.op_curr);
+             power_supply_changed(port->psy);
      }

      return src_pdo;

Regarding selecting PDOs or PPS APDOs, surely we should only notify of a change
when we reach SNK_READY which means a new contract has been established? Until
that point it's possible any requested change could be rejected so why inform
clients before we know the settings have taken effect? I could be missing
something here as it's been a little while since I delved into this, but this
doesn't seem to make sense to me.

I was trying to keep the power_supply_changed call close to the
variables which are used to infer the power supply property values.
Since port->pps_data.max_curr is already updated here and that's used
to infer the CURRENT_MAX a client could still read this before the
request goes through right ?

quoted

@@ -3347,6 +3351,7 @@ static int tcpm_set_charge(struct tcpm_port *port, bool

charge)
                      return ret;
      }
      port->vbus_charge = charge;
+     power_supply_changed(port->psy);
      return 0;
 }

@@ -3530,6 +3535,7 @@ static void tcpm_reset_port(struct tcpm_port *port)
      port->try_src_count = 0;
      port->try_snk_count = 0;
      port->usb_type = POWER_SUPPLY_USB_TYPE_C;
+     power_supply_changed(port->psy);

This is already taken care of at the end of this function, isn't it?

I thought I deleted that. Looks like I didn't. Will send in a patch to
remove that.
Will wait for what we decide for the PPS case so that I can send in
both in the same patch.

Thanks,
Badhri

quoted

      port->nr_sink_caps = 0;
      port->sink_cap_done = false;
      if (port->tcpc->enable_frs)

@@ -5957,7 +5963,7 @@ static int tcpm_psy_set_prop(struct power_supply

*psy,
              ret = -EINVAL;
              break;
      }
-
+     power_supply_changed(port->psy);
      return ret;
 }

@@ -6110,6 +6116,7 @@ struct tcpm_port *tcpm_register_port(struct device

*dev, struct tcpc_dev *tcpc)
      err = devm_tcpm_psy_register(port);
      if (err)
              goto out_role_sw_put;
+     power_supply_changed(port->psy);

      port->typec_port = typec_register_port(port->dev, &port->typec_caps);
      if (IS_ERR(port->typec_port)) {
--
2.31.0.rc2.261.g7f71774620-goog