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From:   Justin Tee <justintee8345@gmail.com>
Date:   Thu, 30 Mar 2023 16:43:01 -0700
Message-ID: <CABPRKS-kMVpEEdJPR6_ru6hjqyjxcVaR+FRWNGS1RRChjeFhCg@mail.gmail.com>
Subject: Re: [PATCH v3 4/9] scsi: lpfc: Change to use pci_aer_clear_uncorrect_error_status()
To:     Bjorn Helgaas <helgaas@kernel.org>
Cc:     Zhuo Chen <chenzhuo.1@bytedance.com>,
        James Smart <james.smart@broadcom.com>,
        Dick Kennedy <dick.kennedy@broadcom.com>,
        Justin Tee <justin.tee@broadcom.com>,
        sathyanarayanan.kuppuswamy@linux.intel.com, bhelgaas@google.com,
        ruscur@russell.cc, oohall@gmail.com, fancer.lancer@gmail.com,
        jdmason@kudzu.us, dave.jiang@intel.com, allenbh@gmail.com,
        jejb@linux.ibm.com, martin.petersen@oracle.com,
        linux-scsi@vger.kernel.org, linux-pci@vger.kernel.org,
        linux-kernel@vger.kernel.org, ntb@lists.linux.dev,
        linuxppc-dev@lists.ozlabs.org
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Hi Bjorn,

> But lpfc_aer_cleanup_state() is visible in the
> "lpfc_aer_state_cleanup" sysfs file, so removing it would break any
> userspace that uses it.
>
> If we can rely on the PCI core to clean up AER errors itself
> (admittedly, that might be a big "if"), maybe lpfc_aer_cleanup_state()
> could just become a no-op?
>
> Any comment from the LPFC folks?

We have notified all users of the lpfc_aer_cleanup_state sysfs entry,
and Broadcom LPFC is okay to no-op.

Regards,
Justin

On Wed, Mar 15, 2023 at 2:39=E2=80=AFPM Bjorn Helgaas <helgaas@kernel.org> =
wrote:
>
> On Tue, Dec 06, 2022 at 04:13:35PM -0600, Bjorn Helgaas wrote:
> > On Wed, Sep 28, 2022 at 06:59:41PM +0800, Zhuo Chen wrote:
> > > lpfc_aer_cleanup_state() requires clearing both fatal and non-fatal
> > > uncorrectable error status.
> >
> > I don't know what the point of lpfc_aer_cleanup_state() is.  AER
> > errors should be handled and cleared by the PCI core, not by
> > individual drivers.  Only lpfc, liquidio, and sky2 touch
> > PCI_ERR_UNCOR_STATUS.
> >
> > But lpfc_aer_cleanup_state() is visible in the
> > "lpfc_aer_state_cleanup" sysfs file, so removing it would break any
> > userspace that uses it.
> >
> > If we can rely on the PCI core to clean up AER errors itself
> > (admittedly, that might be a big "if"), maybe lpfc_aer_cleanup_state()
> > could just become a no-op?
> >
> > Any comment from the LPFC folks?
> >
> > Ideally, I would rather not export pci_aer_clear_nonfatal_status() or
> > pci_aer_clear_uncorrect_error_status() outside the PCI core at all.
>
> Resurrecting this old thread.  Zhuo, can you figure out where the PCI
> core clears these errors, include that in the commit log, and propose
> a patch that makes lpfc_aer_cleanup_state() a no-op, by removing the
> pci_aer_clear_nonfatal_status() call completely?
>
> Such a patch could be sent to the SCSI maintainers since it doesn't
> involve the PCI core.
>
> If it turns out that the PCI core *doesn't* clear these errors, we
> should figure out *why* it doesn't and try to change the PCI core so
> it does.
>
> > > But using pci_aer_clear_nonfatal_status()
> > > will only clear non-fatal error status. To clear both fatal and
> > > non-fatal error status, use pci_aer_clear_uncorrect_error_status().
> > >
> > > Signed-off-by: Zhuo Chen <chenzhuo.1@bytedance.com>
> > > ---
> > >  drivers/scsi/lpfc/lpfc_attr.c | 4 ++--
> > >  1 file changed, 2 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/drivers/scsi/lpfc/lpfc_attr.c b/drivers/scsi/lpfc/lpfc_a=
ttr.c
> > > index 09cf2cd0ae60..d835cc0ba153 100644
> > > --- a/drivers/scsi/lpfc/lpfc_attr.c
> > > +++ b/drivers/scsi/lpfc/lpfc_attr.c
> > > @@ -4689,7 +4689,7 @@ static DEVICE_ATTR_RW(lpfc_aer_support);
> > >   * Description:
> > >   * If the @buf contains 1 and the device currently has the AER suppo=
rt
> > >   * enabled, then invokes the kernel AER helper routine
> > > - * pci_aer_clear_nonfatal_status() to clean up the uncorrectable
> > > + * pci_aer_clear_uncorrect_error_status() to clean up the uncorrecta=
ble
> > >   * error status register.
> > >   *
> > >   * Notes:
> > > @@ -4715,7 +4715,7 @@ lpfc_aer_cleanup_state(struct device *dev, stru=
ct device_attribute *attr,
> > >             return -EINVAL;
> > >
> > >     if (phba->hba_flag & HBA_AER_ENABLED)
> > > -           rc =3D pci_aer_clear_nonfatal_status(phba->pcidev);
> > > +           rc =3D pci_aer_clear_uncorrect_error_status(phba->pcidev)=
;
> > >
> > >     if (rc =3D=3D 0)
> > >             return strlen(buf);
> > > --
> > > 2.30.1 (Apple Git-130)
> > >