Re: [PATCH 3/8] platform: arm64: qcom-hamoa-ec: Switch fan profile based on power supply state

[Konrad Dybcio]

On 7/28/26 7:44 PM, Anvesh Jain P wrote:
> Add the EC command definitions and handler functions for switching and
> reading the EC fan profile.
> 
> Register a power supply notifier so the driver can react to AC/battery
> transitions: on each PSY_EVENT_PROP_CHANGED notification, queue work
> that checks power_supply_is_system_supplied() and, if the AC/battery
> state has actually changed, switches the fan profile to the
> performance profile on AC or the battery-saver profile on battery.
> Track the last-applied state in on_ac_power to avoid redundant EC
> writes. Run the initial sync once at probe time, and defer the actual
> switch to a work item since the notifier callback runs in atomic
> context.
> 
> Serialize the fan profile write under the existing io_lock mutex,
> alongside the other EC command sequences.
> 
> Signed-off-by: Anvesh Jain P <anvesh.p@xxxxxxxxxxxxxxxx>
> ---

[...]

> +static int qcom_ec_set_fan_profile(struct qcom_ec *ec, u8 profile_id)
> +{
> +	int ret;
> +
> +	ret = i2c_smbus_write_byte_data(ec->client, EC_FAN_PROFILE_CMD, profile_id);

Shouldn't all the accesses be serialized after patch 2?

[...]

> +static int qcom_ec_update_profile_from_power_supply(struct qcom_ec *ec)
> +{
> +	int on_ac_power;
> +	u8 profile;
> +	int ret = 0;
> +
> +	on_ac_power = power_supply_is_system_supplied() > 0 ? 1 : 0;

Comparisons already return a boolean value (i.e. the ternary operator is
not necessary here)

> +
> +	profile = on_ac_power ? EC_FAN_PROFILE_BEST_PERF_PLUGGED_IN :
> +				EC_FAN_PROFILE_BETTER_BATT_ON_BATT;

Is being on a (powerful) charger a prerequisite for entering this profile?
Currently plugging in a 5W charger would trigger the switch as well.

Should this instead be exposed as a fan profile for userspace?

Konrad