Messages in this thread | | | Date | Wed, 27 Nov 2013 13:22:27 -0800 | From | Greg KH <> | Subject | Re: [PATCH] PCI: Clear Bus Master bit only on kexec reboot |
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On Wed, Nov 27, 2013 at 12:59:40PM -0700, Khalid Aziz wrote: > On 11/27/2013 12:38 PM, ebiederm@xmission.com wrote: > >Khalid Aziz <khalid.aziz@oracle.com> writes: > > > >>Add a flag to tell the PCI subsystem that kernel is shutting down > >>in prepapration to kexec a kernel. Add code in PCI subsystem to use > >>this flag to clear Bus Master bit on PCI devices only in case of > >>kexec reboot. This fixes https://bugzilla.kernel.org/show_bug.cgi?id=63861 > >>and avoids any other issues caused by clearing Bus Master bit on PCI > >>devices in normal shutdown path. This patch is based on discussion at > >>http://marc.info/?l=linux-pci&m=138425645204355&w=2 > > > >Scratches head. > > > >Given that most devices already call pci_disable_device which clears the > >bus master bit how does this change anything meaningful? > > > >Is is the problem here that most drivers are lazy and have a noop > >shutdown method? > > Yes, that is exactly the problem.
Then fix the drivers please. It's not as if you don't have access to the source for them all...
greg k-h
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