What is the meaning of "deinitialized"?

Hello,

I have a question about data transfer operation of CUDA.

I wrote my kernel code and executed, but the result of computation is strange value…
I checked the return value of CUDA_SAFE_CALL, and found that
after the execution of my kernel function, cuda_error value of cudamemcpy(device to host) and that of cudafree is 4.
(Meanwhile, the return value of cudamalloc or cudamemcpy(host to device) is 0.
before the kernel execution, everything goes well.)

So I checked a comment about cuda_error value in cuda.h, and found the following description.
“CUDA_ERROR_DEINITIALIZED = 4, ///< Driver deinitialized”

I couldn’t understand the meaning of “deinitialized”, so I read NVIDIA programming guide 2.2 and CUDA references, but
there is no description about that.

What is the meaning of “deinitialized”?
Is there any difference between “not initialized” and “deinitialized”??

Perhaps your kernel does something really nasty like reading outside of memory boundaries which causes a segfault? In such case, the driver will kill your CUDA context.