On Tue, 17 Jul 2018, hch@xxxxxx wrote: > On Tue, Jul 17, 2018 at 11:38:53PM +0800, Ming Lei wrote: > > As I said, it is any sd/sr device, which can be put down by runtime PM > > via START_STOP command if it isn't used for a while. > > And in which case do we care that this happens? Consider a low-power system (e.g., embedded applications, tablet computer, etc.) using a USB flash drive. Consider a high-power system with lots of disk drives that consume a lot of power while they are running but not while they are stopped. It's safe to assume that if the kernel can provide a capability like this for users, some people will take advantage of it. Alan Stern
