On Mon, 26 Dec 2005, Dmitry Torokhov wrote: > Device removal could happen at any point, even during suspend transition. > The kernel should be able to handle this scenario therefore implementation > that assumes that device tree is frozen in flawed. As far as I understand > the only thing that does not work at the moment is invoking hotplug handler. The situation isn't all that bad. The device tree can be changed only by calling device_add or device_del (or the corresponding register/unregister routines). That can only be done in process context; hence if processes are frozen it can't happen. Or rather, it can happen only if a suspend() or resume() method tries to do it. If those methods don't try to handle device removal or addition -- which in most cases they shouldn't -- then there's nothing to worry about. It's only oddball situations (like calling the remove method when the driver doesn't define a suspend method) that cause problems. And even then, with most drivers you don't get a hotplug event when the driver is unbound. It happens only with things like usb-storage, that define child devices. Alan Stern
