On Thu, Sep 21, 2017 at 4:57 PM, Mario Limonciello <mario.limonciello@xxxxxxxx> wrote: > For WMI operations that are only Set or Query read or write sysfs > attributes created by WMI vendor drivers make sense. > > For other WMI operations that are run on Method, there needs to be a > way to guarantee to userspace that the results from the method call > belong to the data request to the method call. Sysfs attributes don't > work well in this scenario because two userspace processes may be > competing at reading/writing an attribute and step on each other's > data. > > When a WMI vendor driver declares a set of functions in a > file_operations object the WMI bus driver will create a character > device that maps to those file operations. > > The WMI vendor drivers will be responsible for managing access to > this character device and proper locking on it. > > When a WMI vendor driver is unloaded the WMI bus driver will clean > up the character device. > > @@ -44,12 +44,17 @@ > #include <linux/platform_device.h> > #include <linux/wmi.h> > #include <linux/uuid.h> > +#include <linux/cdev.h> > +#include <linux/idr.h> Keep alphabetical ordering. -- With Best Regards, Andy Shevchenko
