Re: [PATCH V5 02/12] PNPACPI: use whilte list for pnpacpi device enumeration

From: Rafael J. Wysocki
Date: Sun Apr 27 2014 - 17:45:44 EST


On Tuesday, April 08, 2014 12:06:49 AM Zhang Rui wrote:

[...]

> +
> +static int acpi_pnp_scan_handler_attach(struct acpi_device *adev,
> + const struct acpi_device_id *id)
> +{
> + return 1;
> +}
> +
> +static int acpi_pnp_scan_handler_match(char *devid, char *handlerid)
> +{
> + int i;
> +
> + if (memcmp(devid, handlerid, 3))
> + return 0;
> +
> + for (i = 3; i < 7; i++) {
> + /* Not a HEX value */
> + if (!((devid[i] >= '0' && devid[i] <= '9') ||
> + (devid[i] > 'A' && devid[i] <= 'F')))
> + return 0;
> +
> + if ((handlerid[i] != 'X') &&

Hmm. What exactly is the above check for?

> + toupper(devid[i]) != toupper(handlerid[i]))
> + return 0;
> + }
> + return 1;
> +}
> +
> +static struct acpi_scan_handler acpi_pnp_handler = {
> + .ids = acpi_pnp_device_ids,
> + .match = acpi_pnp_scan_handler_match,
> + .attach = acpi_pnp_scan_handler_attach,
> +};
> +
> +bool acpi_is_pnp_device(struct acpi_device *device)
> +{
> + return device->handler == &acpi_pnp_handler;
> +}
> +EXPORT_SYMBOL_GPL(acpi_is_pnp_device);
> +
> +void __init acpi_pnp_init(void)
> +{
> + acpi_scan_add_handler(&acpi_pnp_handler);
> +}
> diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h


--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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