On Thu, Jun 16, 2011 at 10:03:11AM -0700, Sarah Sharp wrote: > > The thing that made me come to this conclusion is the struct scsi_cmnd > > *current_cmnd field of the scsi_device structure that if is not null, in > > uas_queuecommand_lck() you return SCSI_MLQUEUE_DEVICE_BUSY. > > I don't know enough about that piece of code to comment. Matthew? Ah! If the SCSI midlayer sends down a command that _isn't tagged_, we use tag 1 for it, and prevent any other commands from being executed while the untagged command is being executed. Similarly, if any commands are outstanding when the SCSI layer sends down an untagged command, we block until all the tagged commands have finished executing and then the midlayer will resubmit the untagged command. Generally, it only sends down untagged commands early on (ie IDENTIFY and similar). -- 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
