Oliver (or anybody else): Adding dynamic (AKA runtime) power management to the SCSI core is looking a little difficult. (Actually, since as far as I know the SCSI specification takes no heed of power management, perhaps this should be called "idle-device management".) Imagine a SCSI disk has been idle long enough that we want to spin it down. When I/O requests do start to arrive later on, we want to delay them in the request queue until the disk has a chance to spin back up. Or even to fail them, if the user has done a "manual" suspend. These are conflicting requirements. How can we send the START-STOP UNIT commands to spin the disk up/down through the request queue while delaying or failing all others? What happens if one of the START-STOP UNIT commands encounters a problem and the error handler needs to send some commands of its own? Any suggestions or ideas are welcome. Alan Stern - 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
