Re: [PATCH RFC V2 3/3] scsi_mq: enable runtime PM

Alan Stern
2018-07-17T20:54:53Z

On Tue, 17 Jul 2018, hch@lst.de 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