[Intel-gfx] [PATCH v2] drm/i915/huc: Don't try to check HuC status if it's not loaded

[Joonas Lahtinen]

Quoting Ye, Tony (2019-05-22 14:32:41)
>  From UMD perspective, when HuC is not working as expected, usually we 
> look into the kernel log and i915_huc_load_status debugfs to find out 
> why it's not working. It will be helpful to know the reason of the 
> failure from the error code. The typically failures we encountered are 
> "HuC FW not loaded (FW not built into initramfs)" and "HuC FW 
> authentication failed".
> 
> And it looks clearer to me if we can define 0 as "disabled by user" to 
> distinguish it from other errors like ENODEV, ENOPKG and "not 
> authenticated".

Suggestion by Chris for 0/1 for huc_status makes sense to me to reflect if
HuC authentication was succesful or not. Mostly because the name of the
debugfs and func is huc_status. It also nicely maps to a register.

One could have huc_enabled which would then collapse to easy 0/1, but that'd
be bit redundant.

Regards, Joonas