[Intel-gfx] [PATCH] [i915] avoid infinite retries in GuC/HuC loading

[Alexandre Oliva]

On Mar 22, 2023, Rodrigo Vivi <rodrigo.vivi at intel.com> wrote:

> On Sun, Mar 12, 2023 at 04:56:23PM -0300, Alexandre Oliva wrote:
>> 
> Since __uc_fw_auto_select is also called from another place,
> intel_uc_fw_init_early
> out of the intel_uc_fw_fetch infinite loop,

That other place is conceptually, sort of, the first iteration of the
infinite loop.  Before that first separate early-init call, *uc_fw is
returned by devm_drm_dev_alloc to i915_driver_create, so
zero-initialized I presume, in both the guc and the huc cases.

Only if this first call finds a matching entry (setting both
file_{selected,wanted}.path), and the selected entry fails to load, do
we even enter the loop (provided that other conditionals are satisfied)
and look for other entries, using file_selected.path to find how far the
previous call got (and, with the proposed patch, file_wanted.path to
avoid retrying the path we've just tried).

> I hope Daniele and John have a better understanding and can provide
> some guidance or acks here.

I surely appreciate additional eyes and minds that are more acquainted
with the code at hand than I am.  Thanks,

-- 
Alexandre Oliva, happy hacker                https://FSFLA.org/blogs/lxo/
   Free Software Activist                       GNU Toolchain Engineer
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