On Thu, Dec 15, 2011 at 11:21:31AM -0800, Tejun Heo wrote: > SATA link detection requires hot wire and keeping wire hot takes > power. I think it's fair tradeoff to not support hotplug while > powersaving is on. We have warm plug mechanism (the SCSI rescan > trigger via sysfs) after all. It would be nice if things like that is > somehow exported to userland in easy way tho (cc'ing Kay), but I > frankly don't have much idea where that would fit. We expose the ahci_port_cmd field in sysfs, which lets us know whether a port is flagged as hotpluggable or external. Userspace could use that to identify whether a given port can be safely powered off or not. It's not guaranteed - desktop boards with esata ports will typically not have this information available (because the esata port could be plugged into any on-board port), so I think leaving it up to userspace to set the policy makes sense. -- Matthew Garrett | mjg59@xxxxxxxxxxxxx -- 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
