From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Bjorn Helgaas <helgaas@kernel.org>,
David Laight <David.Laight@ACULAB.COM>
Cc: "'Oliver O'Halloran'" <oohall@gmail.com>,
Arnd Bergmann <arnd@arndb.de>, Keith Busch <kbusch@kernel.org>,
Paul Mackerras <paulus@samba.org>,
sparclinux <sparclinux@vger.kernel.org>,
Toan Le <toan@os.amperecomputing.com>,
Greg Ungerer <gerg@linux-m68k.org>,
Marek Vasut <marek.vasut+renesas@gmail.com>,
Rob Herring <robh@kernel.org>,
Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
Sagi Grimberg <sagi@grimberg.me>,
Russell King <linux@armlinux.org.uk>,
Ley Foon Tan <ley.foon.tan@intel.com>,
Christoph Hellwig <hch@lst.de>,
Geert Uytterhoeven <geert@linux-m68k.org>,
Kevin Hilman <khilman@baylibre.com>,
linux-pci <linux-pci@vger.kernel.org>,
Jakub Kicinski <kuba@kernel.org>,
Matt Turner <mattst88@gmail.com>,
"linux-kernel-mentees@lists.linuxfoundation.org"
<linux-kernel-mentees@lists.linuxfoundation.org>,
Guenter Roeck <linux@roeck-us.net>, Ray Jui <rjui@broadcom.com>,
Jens Axboe <axboe@fb.com>,
Ivan Kokshaysky <ink@jurassic.park.msu.ru>,
Shuah Khan <skhan@linuxfoundation.org>,
"bjorn@helgaas.com" <bjorn@helgaas.com>,
Boris Ostrovsky <boris.ostrovsky@oracle.com>,
Richard Henderson <rth@twiddle.net>,
Juergen Gross <jgross@suse.com>,
Bjorn Helgaas <bhelgaas@google.com>,
Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
Scott Branden <sbranden@broadcom.com>,
Jingoo Han <jingoohan1@gmail.com>,
"Saheed O. Bolarinwa" <refactormyself@gmail.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Philipp Zabel <p.zabel@pengutronix.de>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Gustavo Pimentel <gustavo.pimentel@synopsys.com>,
linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
"David S. Miller" <davem@davemloft.net>,
Heiner Kallweit <hkallweit1@gmail.com>
Subject: Re: [RFC PATCH 00/35] Move all PCIBIOS* definitions into arch/x86
Date: Thu, 16 Jul 2020 08:49:21 +1000 [thread overview]
Message-ID: <5d4b3a716f85017c17c52a85915fba9e19509e81.camel@kernel.crashing.org> (raw)
In-Reply-To: <20200715221230.GA563957@bjorn-Precision-5520>
On Wed, 2020-07-15 at 17:12 -0500, Bjorn Helgaas wrote:
> > I've 'played' with PCIe error handling - without much success.
> > What might be useful is for a driver that has just read ~0u to
> > be able to ask 'has there been an error signalled for this device?'.
>
> In many cases a driver will know that ~0 is not a valid value for the
> register it's reading. But if ~0 *could* be valid, an interface like
> you suggest could be useful. I don't think we have anything like that
> today, but maybe we could. It would certainly be nice if the PCI core
> noticed, logged, and cleared errors. We have some of that for AER,
> but that's an optional feature, and support for the error bits in the
> garden-variety PCI_STATUS register is pretty haphazard. As you note
> below, this sort of SERR/PERR reporting is frequently hard-wired in
> ways that takes it out of our purview.
We do have pci_channel_state (via pci_channel_offline()) which covers
the cases where the underlying error handling (such as EEH or unplug)
results in the device being offlined though this tend to be
asynchronous so it might take a few ~0's before you get it.
It's typically used to break potentially infinite loops in some
drivers.
There is no interface to check whether *an* error happened though for
the most cases it will be captured in the status register, which is
harvested (and cleared ?) by some EDAC drivers iirc...
All this lacks coordination, I agree.
Cheers,
Ben.
next prev parent reply other threads:[~2020-07-15 22:52 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CAK8P3a3NWSZw6678k1O2eJ6-c5GuW7484PRvEzU9MEPPrCD-yw@mail.gmail.com>
2020-07-14 18:45 ` [RFC PATCH 00/35] Move all PCIBIOS* definitions into arch/x86 Bjorn Helgaas
2020-07-14 21:02 ` Kjetil Oftedal
2020-07-15 2:14 ` Benjamin Herrenschmidt
2020-07-14 22:01 ` Arnd Bergmann
2020-07-14 23:46 ` Bjorn Helgaas
2020-07-15 2:19 ` Benjamin Herrenschmidt
2020-07-15 6:47 ` Arnd Bergmann
2020-07-15 22:26 ` Benjamin Herrenschmidt
2020-07-15 4:18 ` Oliver O'Halloran
2020-07-15 14:38 ` David Laight
2020-07-15 22:12 ` Bjorn Helgaas
2020-07-15 22:49 ` Benjamin Herrenschmidt [this message]
2020-07-16 8:07 ` David Laight
2020-07-14 23:14 ` Rob Herring
2020-07-15 2:12 ` Benjamin Herrenschmidt
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=5d4b3a716f85017c17c52a85915fba9e19509e81.camel@kernel.crashing.org \
--to=benh@kernel.crashing.org \
--cc=David.Laight@ACULAB.COM \
--cc=arnd@arndb.de \
--cc=axboe@fb.com \
--cc=bhelgaas@google.com \
--cc=bjorn@helgaas.com \
--cc=boris.ostrovsky@oracle.com \
--cc=davem@davemloft.net \
--cc=geert@linux-m68k.org \
--cc=gerg@linux-m68k.org \
--cc=gregkh@linuxfoundation.org \
--cc=gustavo.pimentel@synopsys.com \
--cc=hch@lst.de \
--cc=helgaas@kernel.org \
--cc=hkallweit1@gmail.com \
--cc=ink@jurassic.park.msu.ru \
--cc=jgross@suse.com \
--cc=jingoohan1@gmail.com \
--cc=kbusch@kernel.org \
--cc=khilman@baylibre.com \
--cc=kuba@kernel.org \
--cc=ley.foon.tan@intel.com \
--cc=linux-kernel-mentees@lists.linuxfoundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pci@vger.kernel.org \
--cc=linux@armlinux.org.uk \
--cc=linux@roeck-us.net \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=lorenzo.pieralisi@arm.com \
--cc=marek.vasut+renesas@gmail.com \
--cc=mattst88@gmail.com \
--cc=oohall@gmail.com \
--cc=p.zabel@pengutronix.de \
--cc=paulus@samba.org \
--cc=refactormyself@gmail.com \
--cc=rjui@broadcom.com \
--cc=robh@kernel.org \
--cc=rth@twiddle.net \
--cc=sagi@grimberg.me \
--cc=sbranden@broadcom.com \
--cc=skhan@linuxfoundation.org \
--cc=sparclinux@vger.kernel.org \
--cc=toan@os.amperecomputing.com \
--cc=tsbogend@alpha.franken.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).