ioctl() and driver function d_ioctl return values

[Beesdeckar]

Hello,

I am calling ioctl() with control code created with __IOWR() macro and 
third argument contains address of user-mode structure.
When module's d_ioctl() returns non-zero value then user-mode ioctl() 
returns always -1 and structure in user mode does not contain data 
filled by module.

Are both above things by design ?

Peter