FENCE_ADD_CALLBACK(9)             Device drivers infrastructure             FENCE_ADD_CALLBACK(9)



NAME
       fence_add_callback - add a callback to be called when the fence is signaled

SYNOPSIS
       int fence_add_callback(struct fence * fence, struct fence_cb * cb, fence_func_t func);

ARGUMENTS
       fence
           [in] the fence to wait on

       cb
           [in] the callback to register

       func
           [in] the function to call

DESCRIPTION
       cb will be initialized by fence_add_callback, no initialization by the caller is required.
       Any number of callbacks can be registered to a fence, but a callback can only be
       registered to one fence at a time.

       Note that the callback can be called from an atomic context. If fence is already signaled,
       this function will return -ENOENT (and *not* call the callback)

       Add a software callback to the fence. Same restrictions apply to refcount as it does to
       fence_wait, however the caller doesn't need to keep a refcount to fence afterwards: when
       software access is enabled, the creator of the fence is required to keep the fence alive
       until after it signals with fence_signal. The callback itself can be called from irq
       context.

COPYRIGHT
Kernel Hackers Manual 4.8.                 January 2017                     FENCE_ADD_CALLBACK(9)