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

["Rafael J. Wysocki" <rafael.j.wysocki@intel.com>]

On 4/28/2014 3:40 AM, Zhang Rui wrote:
> On Mon, 2014-04-28 at 00:01 +0200, Rafael J. Wysocki wrote:
>> 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?
>>
> PNP bus supports wildcard in the drivers' id list.
> say, drivers/tty/serial/8250/8250_pnp.c
>        {"WACFXXX"},            /* Wacom tablets */
> means the driver wants to try to probe all the PNP devices start with
> "WACF".

I see.  Maybe you can add a comment explaining this before that 
statement, then?

Rafael