From: Khalid Aziz <khalid.aziz@oracle.com>
To: Matthew Garrett <mjg59@srcf.ucam.org>,
Greg KH <gregkh@linuxfoundation.org>
Cc: cl91tp@gmail.com, gnomes@lxorguk.ukuu.org.uk,
indou.takao@jp.fujitsu.com, linux-pci@vger.kernel.org,
kexec@lists.infradead.org, linux-kernel@vger.kernel.org,
stable@vger.kernel.org, f.otti@gmx.at, khlebnikov@openvz.org,
"Eric W. Biederman" <ebiederm@xmission.com>,
jility09@gmail.com, bhelgaas@google.com, tianyu.lan@intel.com
Subject: Re: [PATCH] PCI: Clear Bus Master bit only on kexec reboot
Date: Wed, 27 Nov 2013 15:18:09 -0700 [thread overview]
Message-ID: <52966FA1.3020606@oracle.com> (raw)
In-Reply-To: <20131127220704.GA15609@srcf.ucam.org>
On 11/27/2013 03:07 PM, Matthew Garrett wrote:
> On Wed, Nov 27, 2013 at 02:01:06PM -0800, Greg KH wrote:
>> Anyway, I really don't care either way, but this seems like something
>> that the drivers should be doing. What suddenly changed that caused
>> this problem to occur that hasn't happened in the years prior to now
>> that drives this to be a stable-kernel issue?
>
> We started clearing the busmaster bit on all devices on shutdown in
> 3.something in order to ensure that DMA wasn't occuring while we were
> in the process of performing a kexec. Some machines freeze on shutdown
> as a result. This patch reverts back to the original behaviour on real
> shutdown, while still avoiding the "This PCI device scribbled over my
> new kernel" kexec case.
>
Thanks for explaining this, Matthew. That was my reasoning exactly for
why this patch should apply to stable. It fixes a real problem some
users are experiencing. Commit log contains the URL to bugzilla entry
for the problem.
--
Khalid
_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec
WARNING: multiple messages have this Message-ID (diff)
From: Khalid Aziz <khalid.aziz@oracle.com>
To: Matthew Garrett <mjg59@srcf.ucam.org>,
Greg KH <gregkh@linuxfoundation.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>,
bhelgaas@google.com, cl91tp@gmail.com, tianyu.lan@intel.com,
khlebnikov@openvz.org, gnomes@lxorguk.ukuu.org.uk,
indou.takao@jp.fujitsu.com, jility09@gmail.com, f.otti@gmx.at,
linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org,
kexec@lists.infradead.org, stable@vger.kernel.org
Subject: Re: [PATCH] PCI: Clear Bus Master bit only on kexec reboot
Date: Wed, 27 Nov 2013 15:18:09 -0700 [thread overview]
Message-ID: <52966FA1.3020606@oracle.com> (raw)
In-Reply-To: <20131127220704.GA15609@srcf.ucam.org>
On 11/27/2013 03:07 PM, Matthew Garrett wrote:
> On Wed, Nov 27, 2013 at 02:01:06PM -0800, Greg KH wrote:
>> Anyway, I really don't care either way, but this seems like something
>> that the drivers should be doing. What suddenly changed that caused
>> this problem to occur that hasn't happened in the years prior to now
>> that drives this to be a stable-kernel issue?
>
> We started clearing the busmaster bit on all devices on shutdown in
> 3.something in order to ensure that DMA wasn't occuring while we were
> in the process of performing a kexec. Some machines freeze on shutdown
> as a result. This patch reverts back to the original behaviour on real
> shutdown, while still avoiding the "This PCI device scribbled over my
> new kernel" kexec case.
>
Thanks for explaining this, Matthew. That was my reasoning exactly for
why this patch should apply to stable. It fixes a real problem some
users are experiencing. Commit log contains the URL to bugzilla entry
for the problem.
--
Khalid
next prev parent reply other threads:[~2013-11-27 22:18 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-27 19:18 [PATCH] PCI: Clear Bus Master bit only on kexec reboot Khalid Aziz
2013-11-27 19:18 ` Khalid Aziz
2013-11-27 19:24 ` Matthew Garrett
2013-11-27 19:24 ` Matthew Garrett
2013-11-27 19:48 ` Khalid Aziz
2013-11-27 19:48 ` Khalid Aziz
2013-11-27 19:53 ` Matthew Garrett
2013-11-27 19:53 ` Matthew Garrett
2013-11-27 19:38 ` Eric W. Biederman
2013-11-27 19:38 ` Eric W. Biederman
2013-11-27 19:59 ` Khalid Aziz
2013-11-27 19:59 ` Khalid Aziz
2013-11-27 21:22 ` Greg KH
2013-11-27 21:22 ` Greg KH
2013-11-27 21:53 ` Matthew Garrett
2013-11-27 21:53 ` Matthew Garrett
2013-11-27 22:01 ` Greg KH
2013-11-27 22:01 ` Greg KH
2013-11-27 22:07 ` Matthew Garrett
2013-11-27 22:07 ` Matthew Garrett
2013-11-27 22:18 ` Khalid Aziz [this message]
2013-11-27 22:18 ` Khalid Aziz
2013-11-28 14:15 ` One Thousand Gnomes
2013-11-28 14:15 ` One Thousand Gnomes
2013-11-27 19:39 ` Greg KH
2013-11-27 19:39 ` Greg KH
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=52966FA1.3020606@oracle.com \
--to=khalid.aziz@oracle.com \
--cc=bhelgaas@google.com \
--cc=cl91tp@gmail.com \
--cc=ebiederm@xmission.com \
--cc=f.otti@gmx.at \
--cc=gnomes@lxorguk.ukuu.org.uk \
--cc=gregkh@linuxfoundation.org \
--cc=indou.takao@jp.fujitsu.com \
--cc=jility09@gmail.com \
--cc=kexec@lists.infradead.org \
--cc=khlebnikov@openvz.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pci@vger.kernel.org \
--cc=mjg59@srcf.ucam.org \
--cc=stable@vger.kernel.org \
--cc=tianyu.lan@intel.com \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.