RE: [PATCH] ACPI: APEI: move edac_init ahead of ghes platform drv register

[Kani, Toshi]

On Monday, August 8, 2022 12:38 PM, Borislav Petkov wrote:
> On Mon, Aug 08, 2022 at 08:17:58PM +0200, Rafael J. Wysocki wrote:
> > This effectively makes EDAC depend on GHES which may not be always
> > valid AFAICS.
> 
> Yes, and this has been getting on my nerves since forever.
> 
> The GHES code which does collect all those errors *forces* the registration of
> an EDAC module which does only the reporting.
> 
> Which cannot be any more backwards.
> 
> What should happen is, GHES inits and starts working on the errors.
> Then, at some point later, ghes_edac loads and starts reporting whatever it
> gets. If there's no EDAC module, it doesn't report them. The same way MCA
> works.
> 
> That's it.
> 
> And then ghes_edac can be made a normal module again and we can get rid
> of this insanity.

The following approach may be considerable:
- Separate ghes_edac_register() into two functions, e.g., ghes_edac_register()
and ghes_edac_init().
- ghes_edac_register() only takes the first if-block with IS_ENABLED() & force_load
check, and then calls a new function, edac_set_owner(mod_name), which simply
sets mod_name to edac_mc_owner.  This allows ghes_edac_register() to run
before edac_init(), and sets edac_mc_owner to prevent chipset-specific edac driver
to be loaded before ghes_edac.
- ghes_edac_init() first calls edac_get_owner() to match with its mod_name.  If so,
it performs the rest of the original ghes_edac_register() procedure.  This
ghes_edac_init() is called from the normal module init path, e.g., module_init().

Thanks,
Toshi