Re: [PATCH 2/3] acpi, nfit: add dimm device notification support

From: Kani, Toshimitsu
Date: Mon Aug 29 2016 - 18:19:54 EST


On Fri, 2016-08-26 at 11:39 -0700, Dan Williams wrote:
> On Fri, Aug 26, 2016 at 11:26 AM, Kani, Toshimitsu <toshi.kani@xxxxxx
> m> wrote:
> >
> > On Tue, 2016-08-23 at 14:54 -0700, Dan Williams wrote:
> > >
> > > Per "ACPI 6.1 Section 9.20.3" NVDIMM devices, children of the
> > > ACPI0012 NVDIMM Root device, can receive health event
> > > notifications.
> > >
> > > Given that these devices are precluded from registering a
> > > notification handler via acpi_driver.acpi_device_ops (due to no
> > > _HID), we use acpi_install_notify_handler() directly.
> >
> > I've confirmed that this ACPI notify handler is called properly.
> >
> > >
> > > The registered handler, acpi_nvdimm_notify(), triggers a poll(2)
> > > event on the nmemX/nfit/flags sysfs attribute when a health event
> > > notification is received.
> >
> > This sounds good idea, but should we document that the value of
> > sysfs 'flags' itself does not get updated?ÂÂUser space program will
> > then need to call its _DSM to get health status.
>
> Yes, this plus the new scrub attribute behavior need documentation.
> I'll prepare a refresh for Documentation/nvdimm/nvdimm.txt.
>
> The need to call a _DSM after a notification event is documented in
> the ACPI spec, but you're right, we do need to connect that language
> to the Linux specific mechanism.

Sounds great. ÂWith that:

Reviewed-by: Toshi Kani <toshi.kani@xxxxxxx>

Thanks!
-Toshi