Re: [PATCH] power: supply: cros_charge-control: adopt EC charge state on probe
Tzung-Bi Shih <[email protected]>
| Newsgroups | org.kernel.vger.linux-pm,dev.linux.lists.chrome-platform,org.kernel.vger.linux-kernel |
|---|---|
| Message-ID | <[email protected]> |
On Mon, Aug 24, 2026 at 10:57:18AM -0500, Matt DeVillier wrote:
> +static int cros_chctl_get_ec_status(struct cros_chctl_priv *priv,
> + struct ec_response_charge_control *resp)
> +{
> + struct ec_params_charge_control req = {
> + .cmd = EC_CHARGE_CONTROL_CMD_GET,
> + };
> +
> + lockdep_assert_held(&priv->lock);
> +
> + return cros_chctl_send_charge_control_cmd(priv->cros_ec, priv->cmd_version,
> + &req, resp);
> +}
This lockdep_assert_held() is unnecessary. While it might appear that the
lock is needed here to protect concurrent command transmissions through
the struct cros_ec_device, the underlying EC communication framework
already handles its own locking for that.
> +static void cros_chctl_set_default_state(struct cros_chctl_priv *priv)
> +{
> + priv->current_behaviour = POWER_SUPPLY_CHARGE_BEHAVIOUR_AUTO;
> + priv->current_start_threshold = 0;
> + priv->current_end_threshold = 100;
> +}
Please add a lockdep_assert_held(). This function modifies the core driver
state fields that the lock is explicitly designed to protect.
> +static int cros_chctl_adopt_ec_mode(struct cros_chctl_priv *priv, u32 mode)
> +{
> + switch (mode) {
> + case CHARGE_CONTROL_NORMAL:
> + priv->current_behaviour = POWER_SUPPLY_CHARGE_BEHAVIOUR_AUTO;
> + return 0;
> + case CHARGE_CONTROL_IDLE:
> + priv->current_behaviour = POWER_SUPPLY_CHARGE_BEHAVIOUR_INHIBIT_CHARGE;
> + return 0;
> + case CHARGE_CONTROL_DISCHARGE:
> + priv->current_behaviour = POWER_SUPPLY_CHARGE_BEHAVIOUR_FORCE_DISCHARGE;
> + return 0;
> + default:
> + dev_warn(priv->dev, "unknown charge control mode %u\n", mode);
> + return -EINVAL;
> + }
> +}
Same here, please add a lockdep_assert_held().
> +static int cros_chctl_init_state(struct cros_chctl_priv *priv)
> +{
> + int ret;
> +
> + lockdep_assert_held(&priv->lock);
> +
> + cros_chctl_set_default_state(priv);
> +
> + /* v1 cannot report current state; force a well-known EC configuration. */
> + if (priv->cmd_version < 2)
> + return cros_chctl_configure_ec(priv);
> +
> + ret = cros_chctl_adopt_ec_state(priv);
> + if (ret < 0) {
> + dev_warn(priv->dev,
> + "failed to read EC charge state (%d), applying defaults\n",
> + ret);
> + cros_chctl_set_default_state(priv);
> + return cros_chctl_configure_ec(priv);
> + }
> +
> + return 0;
> }
Instead of asserting the lock in the function, it would be cleaner to handle
the lock acquisition directly inside this function (e.g., by using guard()).
> @@ -305,13 +435,8 @@ static int cros_chctl_probe(struct platform_device *pdev)
> priv->battery_hook.add_battery = cros_chctl_add_battery;
> priv->battery_hook.remove_battery = cros_chctl_remove_battery;
>
> - priv->current_behaviour = POWER_SUPPLY_CHARGE_BEHAVIOUR_AUTO;
> - priv->current_start_threshold = 0;
> - priv->current_end_threshold = 100;
> -
> - /* Bring EC into well-known state */
> scoped_guard(mutex, &priv->lock)
> - ret = cros_chctl_configure_ec(priv);
> + ret = cros_chctl_init_state(priv);
Following the suggestion above, please move the guard() into
cros_chctl_init_state().