[RFC PATCH v2 27/35] ACPICA: Add new MADT GICC flags fields [code first?]

Rafael J. Wysocki rafael at kernel.org
Fri Sep 15 03:21:08 PDT 2023


On Fri, Sep 15, 2023 at 11:34 AM Salil Mehta <salil.mehta at huawei.com> wrote:
>
>
> > From: Rafael J. Wysocki <rafael at kernel.org>
> > Sent: Friday, September 15, 2023 9:45 AM
> > To: Russell King (Oracle) <linux at armlinux.org.uk>
> > Cc: Salil Mehta <salil.mehta at huawei.com>; Ard Biesheuvel <ardb at kernel.org>;
> > Jonathan Cameron <jonathan.cameron at huawei.com>; James Morse
> > <james.morse at arm.com>; linux-pm at vger.kernel.org; loongarch at lists.linux.dev;
> > linux-acpi at vger.kernel.org; linux-arch at vger.kernel.org; linux-
> > kernel at vger.kernel.org; linux-arm-kernel at lists.infradead.org; linux-
> > riscv at lists.infradead.org; kvmarm at lists.linux.dev; x86 at kernel.org; Jean-
> > Philippe Brucker <jean-philippe at linaro.org>; jianyong.wu at arm.com;
> > justin.he at arm.com
> > Subject: Re: [RFC PATCH v2 27/35] ACPICA: Add new MADT GICC flags fields
> > [code first?]
> >
> > On Fri, Sep 15, 2023 at 9:09 AM Russell King (Oracle)
> > <linux at armlinux.org.uk> wrote:
> > >
> > > On Fri, Sep 15, 2023 at 02:29:13AM +0000, Salil Mehta wrote:
> > > > On x86, during init, if the MADT entry for LAPIC is found to be
> > > > online-capable and is enabled as well then possible and present
> > >
> > > Note that the ACPI spec says enabled + online-capable isn't defined.
> > >
> > > "The information conveyed by this bit depends on the value of the
> > > Enabled bit. If the Enabled bit is set, this bit is reserved and
> > > must be zero."
> > >
> > > So, if x86 is doing something with the enabled && online-capable
> > > state (other than ignoring the online-capable) then technically it
> > > is doing something that the spec doesn't define
> >
> > And so it is wrong.
>
>
> Or maybe, specification has not been updated yet. code-first?

Well, if you are aware of any change requests related to this and
posted as code-first, please let me know.



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