Re: [PATCH v4 4/6] platform/x86: dell-smo8800: Move instantiation of lis3lv02d i2c_client from i2c-i801 to dell-lis3lv02d

Pali Rohár
2024-06-24T18:14:24Z

On Monday 24 June 2024 13:15:16 Hans de Goede wrote:
> +static int match_acpi_device_ids(struct device *dev, const void *data)
> +{

You can mark this function as __init as it is called only from
dell_lis3lv02d_init to free space.

> + const struct acpi_device_id *ids = data;
> +
> + return acpi_match_device(ids, dev) ? 1 : 0;
> +}
> +
> +static int __init dell_lis3lv02d_init(void)
> +{
> + struct device *dev;
> + int err;
> +
> + /*
> + * First check for a matching platform_device. This protects against
> + * SMO88xx ACPI fwnodes which actually do have an I2C resource, which
> + * will already have an i2c_client instantiated (not a platform_device).
> + */
> + dev = bus_find_device(&platform_bus_type, NULL, smo8800_ids, match_acpi_device_ids);
> + if (!dev) {
> + pr_debug("No SMO88xx platform-device found\n");
> + return 0;

Is zero return value expected? Should not be it something like -ENODEV?

> + }
> + put_device(dev);
> +
> + lis3lv02d_dmi_id = dmi_first_match(lis3lv02d_devices);
> + if (!lis3lv02d_dmi_id) {

You can cache the value lis3lv02d_dmi_id->driver_data instead of caching
lis3lv02d_dmi_id pointer and then you can mark lis3lv02d_devices array
as __initconst to free additional space not needed at runtime on x86
machines without accelerometer where CONFIG_DELL_SMO8800=y.

> + pr_warn("accelerometer is present on SMBus but its address is unknown, skipping registration\n");
> + return 0;
> + }
> +
> + /*
> + * Register i2c-bus notifier + queue initial scan for lis3lv02d
> + * i2c_client instantiation.
> + */
> + err = bus_register_notifier(&i2c_bus_type, &i2c_nb);
> + if (err)
> + return err;
> +
> + notifier_registered = true;
> +
> + queue_work(system_long_wq, &i2c_work);
> + return 0;
> +}
> +module_init(dell_lis3lv02d_init);
> +
> +static void __exit dell_lis3lv02d_module_exit(void)
> +{
> + if (!notifier_registered)
> + return;
> +
> + bus_unregister_notifier(&i2c_bus_type, &i2c_nb);
> + cancel_work_sync(&i2c_work);
> + i2c_unregister_device(i2c_dev);
> +}
> +module_exit(dell_lis3lv02d_module_exit);
> +
> +MODULE_DESCRIPTION("lis3lv02d i2c-client instantiation for ACPI SMO88xx devices");
> +MODULE_AUTHOR("Hans de Goede <hansg@kernel.org>");
> +MODULE_LICENSE("GPL");
> --
> 2.45.1
>