From: "Oliver O'Halloran" <oohall@gmail.com>
To: Sam Bobroff <sbobroff@linux.ibm.com>
Cc: linuxppc-dev <linuxppc-dev@lists.ozlabs.org>
Subject: Re: [PATCH 12/14] powerpc/eeh: Add debugfs interface to run an EEH check
Date: Tue, 17 Sep 2019 13:36:42 +1000 [thread overview]
Message-ID: <CAOSf1CGZmtCCKytFtDef+DLkASNFRGJE5z62P2S_t+aY7o9RiA@mail.gmail.com> (raw)
In-Reply-To: <20190917031558.GI21303@tungsten.ozlabs.ibm.com>
On Tue, Sep 17, 2019 at 1:16 PM Sam Bobroff <sbobroff@linux.ibm.com> wrote:
>
> On Tue, Sep 03, 2019 at 08:16:03PM +1000, Oliver O'Halloran wrote:
> > Detecting an frozen EEH PE usually occurs when an MMIO load returns a 0xFFs
> > response. When performing EEH testing using the EEH error injection feature
> > available on some platforms there is no simple way to kick-off the kernel's
> > recovery process since any accesses from userspace (usually /dev/mem) will
> > bypass the MMIO helpers in the kernel which check if a 0xFF response is due
> > to an EEH freeze or not.
> >
> > If a device contains a 0xFF byte in it's config space it's possible to
> > trigger the recovery process via config space read from userspace, but this
> > is not a reliable method. If a driver is bound to the device an in use it
> > will frequently trigger the MMIO check, but this is also inconsistent.
> >
> > To solve these problems this patch adds a debugfs file called
> > "eeh_dev_check" which accepts a <domain>:<bus>:<dev>.<fn> string and runs
> > eeh_dev_check_failure() on it. This is the same check that's done when the
> > kernel gets a 0xFF result from an config or MMIO read with the added
> > benifit that it can be reliably triggered from userspace.
> >
> > Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
>
> Looks good, and I tested it with the next patch and it seems to work.
>
> But I think you should make it clear that this does not work with
> the hardware "EEH error injection" facility accessible via debugfs in
> err_injct (that doesn't seem clear to me from the commit message).
It's not intended to be a separate mechanisms in the long term. I'm
planning on converting this interface to make use the platform defined
error injection mechanism once I can find how to use the PAPR ones
reliably. The idea is to use this as a generic "cause an EEH to happen
on this device" interface for userspace which we can use in test
scripts and the like.
next prev parent reply other threads:[~2019-09-17 3:40 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-03 10:15 EEH + hotplug fixes Oliver O'Halloran
2019-09-03 10:15 ` [PATCH 01/14] powerpc/eeh: Clean up EEH PEs after recovery finishes Oliver O'Halloran
2019-09-17 0:43 ` Sam Bobroff
2019-09-19 10:25 ` Michael Ellerman
2019-09-03 10:15 ` [PATCH 02/14] powerpc/eeh: Fix race when freeing PDNs Oliver O'Halloran
2019-09-17 0:50 ` Sam Bobroff
2019-09-03 10:15 ` [PATCH 03/14] powerpc/eeh: Make permanently failed devices non-actionable Oliver O'Halloran
2019-09-17 0:51 ` Sam Bobroff
2019-09-03 10:15 ` [PATCH 04/14] powerpc/eeh: Check slot presence state in eeh_handle_normal_event() Oliver O'Halloran
2019-09-17 1:00 ` Sam Bobroff
2019-09-17 4:20 ` Oliver O'Halloran
2019-09-03 10:15 ` [PATCH 05/14] powerpc/eeh: Defer printing stack trace Oliver O'Halloran
2019-09-17 1:04 ` Sam Bobroff
2019-09-17 1:45 ` Oliver O'Halloran
2019-09-17 3:35 ` Sam Bobroff
2019-09-17 3:38 ` Oliver O'Halloran
2019-09-03 10:15 ` [PATCH 06/14] powerpc/eeh: Remove stale CAPI comment Oliver O'Halloran
2019-09-03 14:09 ` Andrew Donnellan
2019-09-17 1:04 ` Sam Bobroff
2019-09-03 10:15 ` [PATCH 07/14] powernv/eeh: Use generic code to handle hot resets Oliver O'Halloran
2019-09-17 1:15 ` Sam Bobroff
2019-09-17 7:30 ` Oliver O'Halloran
2019-09-03 10:15 ` [PATCH 08/14] pci-hotplug/pnv_php: Add a reset_slot() callback Oliver O'Halloran
2019-09-03 10:16 ` [PATCH 09/14] pci-hotplug/pnv_php: Add support for IODA3 Power9 PHBs Oliver O'Halloran
2019-09-03 10:16 ` [PATCH 10/14] pci-hotplug/pnv_php: Add attention indicator support Oliver O'Halloran
2019-09-03 10:16 ` [PATCH 11/14] powerpc/eeh: Set attention indicator while recovering Oliver O'Halloran
2019-09-17 1:23 ` Sam Bobroff
2019-09-03 10:16 ` [PATCH 12/14] powerpc/eeh: Add debugfs interface to run an EEH check Oliver O'Halloran
2019-09-17 3:15 ` Sam Bobroff
2019-09-17 3:36 ` Oliver O'Halloran [this message]
2019-09-17 4:23 ` Oliver O'Halloran
2019-09-03 10:16 ` [PATCH 13/14] powerpc/eeh: Add a eeh_dev_break debugfs interface Oliver O'Halloran
2019-09-17 3:19 ` Sam Bobroff
2019-09-03 10:16 ` [PATCH 14/14] selftests/powerpc: Add basic EEH selftest Oliver O'Halloran
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