Why does loading radeonkms via /boot/loader.conf fail ?

[Manish Jain]

Hi,

On FreeBSD 10.3 amd64 with a Radeon R5 230 card, I am trying to figure 
out why does the boot process fail early on, halting in the attempt to 
load radeonkms by setting this in /boot/loader.conf :

radeon_load="YES"
radeonkms_load="YES"

If I do that, the radeon kld does get loaded, but radeonkms does not get 
loaded, halting the boot with a message that the GPU firmware 
(radeonkmsfw_CAICOS_pfp in particular) could not be loaded. The system 
hangs, and has to be cold-booted.

The only way I could boot the system was by escaping to the loader 
prompt and issuing "disable-module radeonkms".

I have a nice hack that solves the problem of auto-loading radeon* 
kld's. Load them via /etc/rc.local :

kldload radeon
kldload radeonkms

The above succeeds very sweetly, but for kicks I need to know why the 
regular method fails, hanging the system dead.

Thanks for any reply.
Manish Jain