Re: [PATCH] acpi: Fix hed module initialization order when it is built-in

[Xiaofei Tan]

Hi Rafael,

在 2024/12/11 1:59, Rafael J. Wysocki 写道:
> On Fri, Nov 15, 2024 at 4:56 AM Xiaofei Tan <tanxiaofei@xxxxxxxxxx> wrote:
> > When the module hed is built-in, the init order is determined by
> > Makefile order.
> Are you sure?

yes

> > That order violates expectations. Because the module
> > hed init is behind evged. RAS records can't be handled in the
> > special time window that evged has initialized while hed not.
> > If the number of such RAS records is more than the APEI HEST error
> > source number, the HEST resources could be occupied all, and then
> > could affect subsequent RAS error reporting.
> Well, the problem is real, but does the change really prevent it from
> happening or does it just increase the likelihood of success?

It can be completely solved if the driver used as built-in way. If build HED as a
module, it not solved.

> In the latter case, and generally speaking too, it would be better to
> add explicit synchronization between evged and hed.
>
> > Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
> > Signed-off-by: Xiaofei Tan <tanxiaofei@xxxxxxxxxx>
> > ---
> >   drivers/acpi/Makefile | 8 +++++++-
> >   1 file changed, 7 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
> > index 61ca4afe83dc..54f60b7922ad 100644
> > --- a/drivers/acpi/Makefile
> > +++ b/drivers/acpi/Makefile
> > @@ -15,6 +15,13 @@ endif
> >
> >   obj-$(CONFIG_ACPI)             += tables.o
> >
> > +#
> > +# The hed.o needs to be in front of evged.o to avoid the problem that
> > +# RAS errors cannot be handled in the special time window of startup
> > +# phase that evged has initialized while hed not.
> > +#
> > +obj-$(CONFIG_ACPI_HED)         += hed.o
> > +
> >   #
> >   # ACPI Core Subsystem (Interpreter)
> >   #
> > @@ -95,7 +102,6 @@ obj-$(CONFIG_ACPI_HOTPLUG_IOAPIC) += ioapic.o
> >   obj-$(CONFIG_ACPI_BATTERY)     += battery.o
> >   obj-$(CONFIG_ACPI_SBS)         += sbshc.o
> >   obj-$(CONFIG_ACPI_SBS)         += sbs.o
> > -obj-$(CONFIG_ACPI_HED)         += hed.o
> >   obj-$(CONFIG_ACPI_EC_DEBUGFS)  += ec_sys.o
> >   obj-$(CONFIG_ACPI_BGRT)                += bgrt.o
> >   obj-$(CONFIG_ACPI_CPPC_LIB)    += cppc_acpi.o
> > --
> > 2.33.0
> .