On Tue, 7 Jan 2014, Phillip Susi wrote: > On 1/7/2014 10:25 AM, Alan Stern wrote: > > This doesn't seem like a good idea. The way to speed up resumes is > > to allow sd's resume routine to return while the disk is still > > spinning up (i.e., make the spin-up asynchronous). There already > > have been patches submitted to do this; I don't know what happened > > to them. > > Sure, if that is your *only* goal. I also want the disk to not spin > up *at all* if possible. There's no sense spinning up all of your > disks every time you resume when you very rarely access some of them. Okay, that's a different matter. There's a much simpler way to accomplish this. The patch below will avoid spinning up drives that were already in runtime suspend when the system sleep started. (If a drive wasn't in runtime suspend then presumably it was used recently; therefore it's likely to be used again in the near future and so it _should_ be spun up.) Warning: This patch is completely untested. I didn't even try to compile it. Still, it should give you a good idea as to what is really needed here. Alan Stern Index: usb-3.13/drivers/scsi/scsi_pm.c =================================================================== --- usb-3.13.orig/drivers/scsi/scsi_pm.c +++ usb-3.13/drivers/scsi/scsi_pm.c @@ -71,14 +71,11 @@ scsi_bus_resume_common(struct device *de { int err = 0; + if (pm_runtime_status_suspended(dev)) + return err; + if (scsi_is_sdev_device(dev)) err = scsi_dev_type_resume(dev, cb); - - if (err == 0) { - pm_runtime_disable(dev); - pm_runtime_set_active(dev); - pm_runtime_enable(dev); - } return err; } -- 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