Messages in this thread | | | From | Dan Williams <> | Date | Fri, 26 Aug 2016 11:39:23 -0700 | Subject | Re: [PATCH 2/3] acpi, nfit: add dimm device notification support |
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On Fri, Aug 26, 2016 at 11:26 AM, Kani, Toshimitsu <toshi.kani@hpe.com> 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? User 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.
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