Char device write repeating

I have a character device that I am calling write on and which is succeeding, but which is repeatedly executing. I have hard coded the return value to one, so I don't think the userland standard library is retrying but I could be wrong. Can anybody tell me why write would be re-executed by the kernel and how to fix it? I dont actually copy_from_user, I just need this in order to signal kernel land.