Re: [PATCH 04/12] libata-hp-prep: update ata_scsi_find_dev() and friends

[Tejun Heo <htejun@gmail.com>]

Jeff Garzik wrote:
> Tejun Heo wrote:
>> +static struct ata_device * ata_find_dev(struct ata_port *ap, int id)
>> +{
>> +    if (likely(id == 0 || (id == 1 && ap->flags & ATA_FLAG_SLAVE_POSS)))
>> +        return &ap->device[id];
>> +    return NULL;
> 
>>  static struct ata_device *
>>  ata_scsi_find_dev(struct ata_port *ap, const struct scsi_device 
>> *scsidev)
>>  {
>> -    struct ata_device *dev;
>> -
>> -    /* skip commands not addressed to targets we simulate */
>> -    if (likely(scsidev->id < ATA_MAX_DEVICES))
>> -        dev = &ap->device[scsidev->id];
>> -    else
>> -        return NULL;
> 
> 
> You replace a '<' test with a more complex test, which must then be 
> modified when we start supporting Port Multipliers.
> 
> It is more simple, and easier, to keep the 'id < ATA_MAX_DEVICES' test 
> AFAICS.

The change is to catch user warm plug request for impossible devices.  I 
think it's worth to change it two times as it makes user visible 
interface consistent.

-- 
tejun