> > > > > > > So the question is, does the ACPI core have to do that and if so, then why? > > > > > > > > > > > > The problem is that acpi_memory_devcie_remove() can fail. However, > > > > > > device_release_driver() is a void function, so it cannot report its > > > > > > error. Here are function flows for SCI, sysfs eject and unbind. > > > > > > > > > > Then don't ever let acpi_memory_device_remove() fail. If the user wants > > > > > it gone, it needs to go away. Just like any other device in the system > > > > > that can go away at any point in time, you can't "fail" that. > > > > > > > > That would be ideal, but we cannot delete a memory device that contains > > > > kernel memory. I am curious, how do you deal with a USB device that is > > > > being mounted in this case? > > > > > > As the device is physically gone now, we deal with it and clean up > > > properly. > > > > > > And that's the point here, what happens if the memory really is gone? > > > You will still have to handle it now being removed, you can't "fail" a > > > physical removal of a device. > > > > > > If you remove a memory device that has kernel memory on it, well, you > > > better be able to somehow remap it before the kernel needs it :) > > > > :) > > > > Well, we are not trying to support surprise removal here. All three > > use-cases (SCI, eject, and unbind) are for graceful removal. Therefore > > they should fail if the removal operation cannot complete in graceful > > way. > > Then handle that in the ACPI bus code, it isn't anything that the driver > core should care about, right? Unfortunately not. Please take a look at the function flow for the unbind case in my first email. This request directly goes to driver_unbind(), which is a driver core function. > And odds are, eventually you will have to handle surprise removal, it's > only a matter of time :) Hardware guys will have hard time to support it before software guys can do something here... Staff like cache coherency is a devil. Thanks, -Toshi -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>