Cuda on dynamic dll plugin: error 3 after graphics card undock/redock

Hi everyone!

I have a Microsoft Surface Book 2 which allows the user to undock the dedicated GTX 1050 graphics card and keyboard from the base computer, running on windows 10 x64 and cuda 9.2.

Now I have created a simple application and a dynamic dll:

-The dynamic dll contains the following code on an exported function:

int count;
cudaError_t error = cudaGetDeviceCount(&count);
printf("%i %i\n",count,error);fflush(stdout);

-The main application perform a loadlibrary on the dll, then getprocaddress on this method, then calls it, then freelibrary. This is encapsulated in a loop running it every minute

Everything works well when the dedicated graphics card stays docked, every minute, I get the same output: 1 dedicaded graphics card, error is 0.

Now, after a few loop iterations, if I undock the grahics card then redock it after a bit, I get error code 3 (initialization error), and the only way to make it work again is to restart the app.

Note that if instead of using a dll, I call the code directly in the main application, this scenario provides the correct output after the redock.

Why am I using a dynamic dll then: I want to be able to undock the graphics card during runtime after freeing the dll. For now it works for the first undock but I am unable to reinitialize gpu resources after the redock without having to restart my application.

Thank you very much for your help!

You may wish to file a bug. The instructions are linked in a sticky post at the top of this sub-forum. Note that if you do so, it’s likely that you will be asked for complete codes/projects to reproduce all the observations here.

Thanks! The bug is posted here: