[1/3] ACPI / adxl: Address translation interface using ACPI DSM

["Luck, Tony" <tony.luck@intel.com>]

On Wed, Oct 10, 2018 at 11:08:37PM +0200, Rafael J. Wysocki wrote:
> > +config ACPI_ADXL
> > +       bool "Physical address to DIMM address translation"
> > +       def_bool n
> > +       help
> > +         Enable interface that calls into BIOS using a DSM (device
> > +         specific method) to convert system physical addresses
> > +         to DIMM (socket, channel, rank, dimm, etc.).
> > +         Only available on some servers.
> > +         Used by newer EDAC drivers.
> 
> I'm still not sure why this has to be a user-selectable option.  If
> the plan is to select it from the drivers that need it, why do we need
> to ask about it?  And what if it is enabled, but no drivers use it?
> Will it just be dead code then?

Ah, now I see what you mean.  I should make this:

config ACPI_ADXL
        def_bool n

right? So the user isn't plagued by a question they don't understand.
It will only be set if some other driver that need it selects it. So
no way to include dead code.

> > +       obj = acpi_evaluate_dsm_typed(handle, &adxl_guid, ADXL_REVISION,
> > +                                     cmd, argv, ACPI_TYPE_PACKAGE);
> > +       if (!obj) {
> > +               pr_info("Empty obj\n");
> 
> pr_debug() perhaps?  It is somewhat devoid of details anyway.

I'll make the message more meaningful. I think I want to keep it
at higher than "debug" threshold so that we can diagnose problems
from the first report, without having to ask for a rerun with a
new "dmesg" level.

Realistically this should never happen. If it does, its likely
a BIOS bug.

Thanks for the review.

-Tony