Re: [PATCH V3 18/20] RISC-V: Add ACPI initialization in setup_arch()

[Sunil V L <sunilvl@ventanamicro.com>]

On Mon, Mar 06, 2023 at 09:17:34PM +0000, Conor Dooley wrote:
> On Fri, Mar 03, 2023 at 07:06:45PM +0530, Sunil V L wrote:
> > Initialize the ACPI core for RISC-V during boot.
> > 
> > ACPI tables and interpreter are initialized based on
> > the information passed from the firmware and the value of
> > the kernel parameter 'acpi'.
> > 
> > With ACPI support added for RISC-V, the kernel parameter 'acpi'
> > is also supported on RISC-V. Hence, update the documentation.
> > 
> > Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
> > Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> > Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
> > ---
> 
> > +static int __init acpi_fadt_sanity_check(void)
> > +{
> > +	struct acpi_table_header *table;
> > +	struct acpi_table_fadt *fadt;
> > +	acpi_status status;
> > +	int ret = 0;
> > +
> > +	/*
> > +	 * FADT is required on riscv; retrieve it to check its presence
> > +	 * and carry out revision and ACPI HW reduced compliancy tests
> > +	 */
> > +	status = acpi_get_table(ACPI_SIG_FADT, 0, &table);
> > +	if (ACPI_FAILURE(status)) {
> > +		const char *msg = acpi_format_exception(status);
> > +
> > +		pr_err("Failed to get FADT table, %s\n", msg);
> > +		return -ENODEV;
> > +	}
> > +
> > +	fadt = (struct acpi_table_fadt *)table;
> > +
> > +	/*
> > +	 * Revision in table header is the FADT Major revision, and there
> > +	 * is a minor revision of FADT.
> 
> What is the point of this part of the comment? Isn't it obvious from the
> below code that you expect a major and minor revision?
> If feel like you're trying to make a point in it, but the point has been
> lost :/
> 
It just highlights that major and minor revision fields are in two
different places. Let me remove this comment since it is part of the
spec anyway.

Thanks,
Sunil