PSP_VMBX_POLLING_LIMIT too big

[Mario Limonciello]

Hi,

In amd-staging-drm-next 46fe6312082c ("drm/amdgpu: update retry times 
for psp BL wait") and upstream a11156ff6f41 ("drm/amdgpu: update retry 
times for psp BL wait") the number of loops for 
psp_v13_0_wait_for_bootloader() to try again increased significantly.

It went from 10 loops to 20k loops.  Essentially this means that the 
function can "effectively" no longer fail.

I've got an issue I'm looking at where runtime resume for a dGPU fails, 
and because of this change the system gets stuck in a never ending busy 
loop instead of cleanly returning an error code to the caller.  The 
outcome is the system appears hung while the 20k loops run instead of 
just the dGPU failing to resume.

Is this 20k value really required?  Or can we reduce it back to 
something more manageable?

Thanks,