Re: [PATCH v2 2/3] nfit, libnvdimm: allow an ARS scrub to be triggered on demand

From	Dan Williams <dan.j.williams@intel.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH v2 2/3] nfit, libnvdimm: allow an ARS scrub to be triggered on demand
Date	2016-07-21 21:50 +0200
Message-ID	<rXs8N-3wK-9@gated-at.bofh.it> (permalink)
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On Thu, Jul 21, 2016 at 12:40 PM, Linda Knippers <linda.knippers@hpe.com> wrote:
> On 07/20/2016 09:50 PM, Vishal Verma wrote:
>> Normally, an ARS (Address Range Scrub) only happens at
>> boot/initialization time. There can however arise situations where a
>> bus-wide rescan is needed - notably, in the case of discovering a latent
>> media error, we should do a full rescan to figure out what other sectors
>> are bad, and thus potentially avoid triggering an mce on them in the
>> future. Also provide a sysfs trigger to start a bus-wide scrub.
>
> I don't see anything in here that checks to see if the platform actually
> supports ARS before setting all this stuff up.  Setting up an MCE handler
> and exposing a sysfs trigger for something that is optional and perhaps
> not implemented doesn't seem helpful.  Or is there a check that I missed?

We'll get -ENOTTY to ars_start(), but you're right it's a good idea to
hide the scrub attribute if a platform does not have ars support.

Vishal, can you add an is_visible() routine to
acpi_nfit_attribute_group() to hide 'scrub' on platforms that do not
implement the ARS commands?

Thread

[PATCH v2 2/3] nfit, libnvdimm: allow an ARS scrub to be triggered on demand Vishal Verma <vishal.l.verma@intel.com> - 2016-07-21 04:00 +0200
  Re: [PATCH v2 2/3] nfit, libnvdimm: allow an ARS scrub to be  triggered on demand Dan Williams <dan.j.williams@intel.com> - 2016-07-21 18:00 +0200
    Re: [PATCH v2 2/3] nfit, libnvdimm: allow an ARS scrub to be  triggered on demand Vishal Verma <vishal.l.verma@intel.com> - 2016-07-21 20:10 +0200
  Re: [PATCH v2 2/3] nfit, libnvdimm: allow an ARS scrub to be  triggered on demand Dan Williams <dan.j.williams@intel.com> - 2016-07-21 21:50 +0200
    Re: [PATCH v2 2/3] nfit, libnvdimm: allow an ARS scrub to be  triggered on demand Dan Williams <dan.j.williams@intel.com> - 2016-07-21 22:00 +0200

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