- int __check_region(struct resource * parent, resource_size_t start, resource_size_t n);
- parent resource descriptor
- resource start address
- resource region size
Returns 0 if the region is free at the moment it is checked, returns -EBUSY if the region is busy.
This function is deprecated because its use is racy. Even if it returns 0, a subsequent call to request_region may fail because another driver etc. just allocated the region. Do NOT use it. It will be removed from the kernel.