On Mon, 12 Aug 2013, Oliver Neukum wrote: > Hi, > > I got a bug report about an enclosure that mishandles READ_CAPACITY10. > I don't want to introduce yet another quirk. So what about basing this > on USB version? > @@ -211,8 +212,12 @@ static int slave_configure(struct scsi_device *sdev) > /* > * Many devices do not respond properly to READ_CAPACITY_16. > * Tell the SCSI layer to try READ_CAPACITY_10 first. > + * However some USB 3.0 drive enclosures return capacity > + * modulo 2TB > */ > - sdev->try_rc_10_first = 1; > + usb_version = le16_to_cpu(us->pusb_dev->descriptor.bcdUSB); > + if (usb_version < '3' * 0x100) Don't you mean 0x300? '3' * 0x100 is really equal to 0x3300. > + sdev->try_rc_10_first = 1; This may be a reasonable thing to do, although there's always a risk that it will cause a regression. I have definitely seen one or two reports about drives doing this, but I don't remember whether they claimed to be USB-2 or USB-3. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
