Am Dienstag, 20. Oktober 2009 20:34:36 schrieb Alan Stern: > On Tue, 20 Oct 2009, Oliver Neukum wrote: > > Am Dienstag, 20. Oktober 2009 18:10:39 schrieb Alan Stern: > > > Oliver: > > > > > > There are a couple of significant differences between the existing USB > > > runtime PM code and the new framework. [..] > > I am sure it does not. Under the current rules a driver must not touch > > the counter after it has been disconnected and there's no reason to > > touch it as a device is disconnected, because usbcore is about to > > take charge of it. > > True. Well, now there _will_ be a reason to touch it as a device is > disconnected. > > The alternative, of course, is to keep intf->pm_usage_cnt and have > usbcore mediate the actual changes to the counter in struct device. > Should we do that? In the long run that would be trouble. [..] > Quite so. Matt, what do you think? The downside is that people or > packages might try to enable autosuspend in cases where they shouldn't, > such as drives needing to spin down or needing a SYNCHRONIZE CACHE > command before suspend. Unforunately there's no way the kernel can > tell the good cases from the bad. We can however have the storage driver call the scsi devices' suspend handlers. Regards Oliver -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
