On 11/18/2012 10:38 PM, Tejun Heo wrote: > Hello, Aaron. Hi, > > On Wed, Nov 14, 2012 at 09:32:27AM +0800, Aaron Lu wrote: >>> I don't think you're supposed to use dev->private_data from libata >>> core layer. Just add a new field. Nobody cares about adding 8 more >>> bytes to struct ata_device and spending 8 more bytes is way better >>> than muddying the ownership of ->private_data. >> >> OK. >> And just out of curiosity, who's supposed to use device's private_data? >> I didn't find any user for ata_device's private_data in libata. > > All the ->private_data fields are to be used by low level drivers > (ahci, ata_piix, pata_via...). Given the twisted nature of ATA > devices, it's a bit surprising that no driver yet found a need for > ata_dev->private_data. For most SATA controllers, port to device is > one to one so maybe ap->private_data is enough. > >>> And this gets completely wrong. What if the device supports DA and >>> low level driver makes use of ->private_data? >> >> I didn't find any user of ata_device's private_data, so I used it for >> ZPODD. But if this is dangerous, I'll use a new field. > > As there currently is no other user, it won't break anything but yeah > please add a properly typed and named field. OK, and thanks for the suggestion. -Aaron > > Thanks. > -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
