From: "Kani, Toshimitsu" <toshi.kani@hpe.com>
To: Dan Williams <dan.j.williams@intel.com>
CC: "Rafael J. Wysocki" <rjw@rjwysocki.net>,
        Vishal L Verma <vishal.l.verma@intel.com>,
        "Knippers, Linda" <linda.knippers@hpe.com>,
        "linux-nvdimm@lists.01.org" <linux-nvdimm@lists.01.org>,
        Linux ACPI <linux-acpi@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH v3] acpi/nfit: Issue Start ARS to retrieve existing
 records
Thread-Topic: [PATCH v3] acpi/nfit: Issue Start ARS to retrieve existing
 records
Thread-Index: AQHS50L3HSVE8J+HeUuX5s62QAHN2aI6290AgAHae4A=
Date: Fri, 30 Jun 2017 01:47:21 +0000
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> > ACPI 6.2 defines in section 9.20.7.2 that the OSPM may call a Start
> > ARS with Flags Bit [1] set upon receiving the 0x81 notification.
> >
> >   Upon receiving the notification, the OSPM may decide to issue
> >   a Start ARS with Flags Bit [1] set to prepare for the retrieval
> >   of existing records and issue the Query ARS Status function to
> >   retrieve the records.
> >
> > Add support to call a Start ARS from acpi_nfit_uc_error_notify()
> > with ND_ARS_RETURN_PREV_DATA set when HW_ERROR_SCRUB_ON is not
> set.
> >
> > Link: http://www.uefi.org/sites/default/files/resources/ACPI_6_2.pdf
> > Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
> > Cc: Dan Williams <dan.j.williams@intel.com>
> > Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
> > Cc: Vishal Verma <vishal.l.verma@intel.com>
> > Cc: Linda Knippers <linda.knippers@hpe.com>
> > ---
> > v3 (2/2): Add flags info to acpi_nfit_desc (Dan Williams)
> > ---
> >  drivers/acpi/nfit/core.c   |   11 ++++++++---
> >  drivers/acpi/nfit/mce.c    |    2 +-
> >  drivers/acpi/nfit/nfit.h   |    3 ++-
> >  include/uapi/linux/ndctl.h |    1 +
> >  4 files changed, 12 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
> > index cc22778..7e08ee0 100644
> > --- a/drivers/acpi/nfit/core.c
> > +++ b/drivers/acpi/nfit/core.c
> > @@ -1031,7 +1031,7 @@ static ssize_t scrub_store(struct device *dev,
> >         if (nd_desc) {
> >                 struct acpi_nfit_desc *acpi_desc = to_acpi_desc(nd_desc);
> >
> > -               rc = acpi_nfit_ars_rescan(acpi_desc);
> > +               rc = acpi_nfit_ars_rescan(acpi_desc, 0);
> >         }
> >         device_unlock(dev);
> >         if (rc)
> > @@ -2051,6 +2051,7 @@ static int ars_start(struct acpi_nfit_desc *acpi_desc,
> struct nfit_spa *nfit_spa
> >         memset(&ars_start, 0, sizeof(ars_start));
> >         ars_start.address = spa->address;
> >         ars_start.length = spa->length;
> > +       ars_start.flags = acpi_desc->ars_start_flags;
> 
> Hmm don't we also need a statement like this in ars_continue()?

Good point.  Will set flags in ars_continue().
 
> >         if (nfit_spa_type(spa) == NFIT_SPA_PM)
> >                 ars_start.type = ND_ARS_PERSISTENT;
> >         else if (nfit_spa_type(spa) == NFIT_SPA_VOLATILE)
> > @@ -2613,6 +2614,7 @@ static int acpi_nfit_register_regions(struct
> acpi_nfit_desc *acpi_desc)
> >                                 return rc;
> >                 }
> >
> > +       acpi_desc->ars_start_flags = 0;
> 
> ...and I would think the ND_ARS_RETURN_PREV_DATA context would only be
> valid for the duration of the current scrub, so we should clear the
> flags at the end of acpi_nfit_scrub().

Agreed.

Thanks!
-Toshi