Hello, Aaron. 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. Thanks. -- tejun -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html