Re: [PATCH v2 2/3] ACPI/APEI: Force fatal AER severity when bus has been reset

Chen Gong
2013-06-05T02:04:04Z

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On Tue, Jun 04, 2013 at 11:54:34AM -0600, Bjorn Helgaas wrote:
> Date: Tue, 4 Jun 2013 11:54:34 -0600
> From: Bjorn Helgaas <bhelgaas@google.com>
> To: Betty Dall <betty.dall@hp.com>, rjw@sisk.pl, ying.huang@intel.com,
> linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org,
> linux-pci@vger.kernel.org
> Subject: Re: [PATCH v2 2/3] ACPI/APEI: Force fatal AER severity when bus
> has been reset
> User-Agent: Mutt/1.5.21 (2010-09-15)
>
> On Tue, Jun 04, 2013 at 03:53:36AM -0400, Chen Gong wrote:
> > On Thu, May 30, 2013 at 08:39:28AM -0600, Betty Dall wrote:
> > > Date: Thu, 30 May 2013 08:39:28 -0600
> > > From: Betty Dall <betty.dall@hp.com>
> > > To: rjw@sisk.pl, bhelgaas@google.com
> > > Cc: ying.huang@intel.com, linux-acpi@vger.kernel.org,
> > > linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, Betty Dall
> > > <betty.dall@hp.com>
> > > Subject: [PATCH v2 2/3] ACPI/APEI: Force fatal AER severity when bus has
> > > been reset
> > > X-Mailer: git-send-email 1.7.7.6
> > >
> > > The CPER error record has a reset bit that indicates that the platform
> > > has reset the bus. The reset bit can be set for any severity error
> > > including recoverable. From the AER code path's perspective,
> > > any error is fatal if the bus has been reset. This patch upgrades the
> > > severity of the AER recovery to AER_FATAL whenever the CPER error record
> > > indicates that the bus has been reset.
> > >
> > > Changes since v1:
> > > Fixed a typo in comment.
> > >
> > > Signed-off-by: Betty Dall <betty.dall@hp.com>
> > > ---
> > >
> > > drivers/acpi/apei/ghes.c | 21 ++++++++++++++++++++-
> > > 1 files changed, 20 insertions(+), 1 deletions(-)
> > >
> > >
> > > diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
> > > index d668a8a..1c67d5a 100644
> > > --- a/drivers/acpi/apei/ghes.c
> > > +++ b/drivers/acpi/apei/ghes.c
> > > @@ -451,7 +451,26 @@ static void ghes_do_proc(struct ghes *ghes,
> > > int aer_severity;
> > > devfn = PCI_DEVFN(pcie_err->device_id.device,
> > > pcie_err->device_id.function);
> > > - aer_severity = cper_severity_to_aer(sev);
> > > + /*
> > > + * Some Firmware First implementations
> > > + * put the device in SBR to contain
> > > + * the error. This is indicated by the
> > > + * CPER Section Descriptor Flags reset
> > > + * bit which means the component must
> > > + * be re-initialized or re-enabled
> > > + * prior to use. Promoting the AER
> > > + * serverity to FATAL will cause the
> > > + * AER code to link_reset and allow
> > > + * drivers to reprogram their cards.
> > > + */
> > > + if (gdata->flags & CPER_SEC_RESET)
> > > + aer_severity = cper_severity_to_aer(
> > > + CPER_SEV_FATAL);
> > > + else
> > > + aer_severity =
> > > + cper_severity_to_aer(sev);
> > > +
> > > +
> >
> > How about this?
> > if (gdata->flags & CPER_SEC_RESET)
> > sev = CPER_SEV_FATAL;
> > cper_severity_to_aer(sev);
>
> No. If the object is to make the severity AER_FATAL, you should just
> do that. You shouldn't fiddle around with the CPER severity, because
> then you depend on the mapping performed by cper_severity_to_aer().
>
> >
> > > aer_recover_queue(pcie_err->device_id.segment,
> > > pcie_err->device_id.bus,
> > > devfn, aer_severity);
>
> In other words, something like the patch below. I don't really care
> if you use the original "if" above that only sets aer_severity once,
> or if you overwrite it as below. I overwrote it because it doesn't
> wrap as many lines. ghes_do_proc() really should just call helpers
> so the interesting code doesn't have to be indented three and four
> tab stops.
>
>
> ACPI/APEI: Force fatal AER severity when component has been reset
>
> The CPER error record has a reset bit that indicates that the platform has
> reset the component. The reset bit can be set for any severity error
> including recoverable. From the AER code path's perspective, any error is
> fatal if the component has been reset. This patch upgrades the severity of
> the AER recovery to AER_FATAL in this case.
>
> diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
> index d668a8a..ab31551 100644
> --- a/drivers/acpi/apei/ghes.c
> +++ b/drivers/acpi/apei/ghes.c
> @@ -449,9 +449,19 @@ static void ghes_do_proc(struct ghes *ghes,
> pcie_err->validation_bits & CPER_PCIE_VALID_AER_INFO) {
> unsigned int devfn;
> int aer_severity;
> +
> devfn = PCI_DEVFN(pcie_err->device_id.device,
> pcie_err->device_id.function);
> aer_severity = cper_severity_to_aer(sev);
> +
> + /*
> + * If firmware reset the component to contain
> + * the error, we must reinitialize it before
> + * use, so treat it as a fatal AER error.
> + */
> + if (gdata->flags & CPER_SEC_RESET)
> + aer_severity = AER_FATAL;
> +
> aer_recover_queue(pcie_err->device_id.segment,
> pcie_err->device_id.bus,
> devfn, aer_severity);
>

The patch looks good to me.

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