On Mon, 7 Jan 2008, Rafael J. Wysocki wrote: > Please see the patch at: http://lkml.org/lkml/2008/1/6/298 . It represents my > current idea about how to do that. It has some problems. First, note that the list manipulations in dpm_suspend(), device_power_down(), and so on aren't protected by dpm_list_mtx. So your patch could corrupt the list pointers. Are you assuming that no other threads can be running at this time? Note also that device_pm_destroy_suspended() does up(&dev->sem), but it doesn't know whether or not dev->sem was locked to begin with. Do you want to rule out the possibility of a driver's suspend or remove methods calling destroy_suspended_device() on its own device? With your synchronous approach, this would mean that the suspend/resume method would indirectly end up calling the remove method. This is dangerous at best; with USB it would be a lockdep violation. With an asynchronous approach, on the other hand, this wouldn't be a problem. Alan Stern - To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
