On Fri, 23 Jun 2006, Linus Torvalds wrote: > Ok, here. > > This simple patch is nothing but cleanups, cleanups, cleanups. > - "suspend_prepare()" is called for every device (with the semaphore > held, you are _not_ allowed to try to unlink yourself in the prepare > function) There should be a big fat warning about this somewhere, maybe added to the documentation. It's quite possible for dpm_list_sem to be acquired while holding a device's lock; since the suspend_prepare() method is called while holding dpm_list_sem it therefore mustn't do _anything_ to acquire any device's lock. That includes plenty of other actions in addition to unregistering the device. In particular, it may complicate synchronization between suspend_prepare() and the rest of the driver. Alan Stern
