[PATCH (resend) 3/8] winebus.sys: Implement removing IOHID devices

[Ken Thomases]

On Nov 4, 2016, at 12:26 AM, Ken Thomases <ken at codeweavers.com> wrote:
> 
> On Nov 3, 2016, at 7:15 AM, Aric Stewart <aric at codeweavers.com> wrote:
>> 
>> static int compare_platform_device(DEVICE_OBJECT *device, void *platform_dev)
>> {
>> -    return 0;
>> +    IOHIDDeviceRef dev1 = *(IOHIDDeviceRef*)get_platform_private(device);
>> +    IOHIDDeviceRef dev2 = (IOHIDDeviceRef)platform_dev;
>> +    return dev1 == dev2;
> 
> The return value here has the reverse sense from how the caller interprets it.  The caller, bus_find_hid_device(), interprets it like the result from strcmp() or memcmp().  A value of 0 means equal.  Here, you're returning true (1) when the devices are equal.

By the way, I would recommend that you change this vtable entry to be equal_platform_device (or same_platform_device or matches_platform_device) and make its return type a boolean which is true when the devices are equal and false otherwise.

You can't really do the strcmp/memcmp scheme where < 0 means less than and > 0 means greater than.  Put another way, in the current scheme there's no clear value to return for "not equal" when the bus can't support an ordering of devices.

-Ken