doc/chapters/advanced-api.texi: add doc for starpu_driver_run() and clarify starpu_driver_run_once()

doc/chapters/advanced-api.texi

@@ -701,8 +701,14 @@ Initialize the given driver. Returns 0 on success, -EINVAL if
 STARPU_CUDA_WORKER or STARPU_OPENCL_WORKER).
 @end deftypefun
 
+@deftypefun int starpu_driver_run ({struct starpu_driver *}@var{d})
+Run the driver until it receives a request to terminate, then returns 0 on success, -EINVAL if
+@code{d->type} is not a valid StarPU device type (STARPU_CPU_WORKER,
+STARPU_CUDA_WORKER or STARPU_OPENCL_WORKER).
+@end deftypefun
+
 @deftypefun int starpu_driver_run_once (struct starpu_driver *@var{d})
-Runs the driver for a while, then returns 0 on success, -EINVAL if
+Run the driver once, then returns 0 on success, -EINVAL if
 @code{d->type} is not a valid StarPU device type (STARPU_CPU_WORKER,
 STARPU_CUDA_WORKER or STARPU_OPENCL_WORKER).
 @end deftypefun