| Date | Thu, 20 Aug 2020 09:29:24 -0400 | From | Sasha Levin <> | Subject | Re: [PATCH 5.8 164/232] PCI: hv: Fix a timing issue which causes kdump to fail occasionally |
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On Thu, Aug 20, 2020 at 01:00:51PM +0000, Michael Kelley wrote: >From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Sent: Thursday, August 20, 2020 2:20 AM >> >> From: Wei Hu <weh@microsoft.com> >> >> [ Upstream commit d6af2ed29c7c1c311b96dac989dcb991e90ee195 ] >> >> Kdump could fail sometime on Hyper-V guest because the retry in >> hv_pci_enter_d0() releases child device structures in hv_pci_bus_exit(). >> >> Although there is a second asynchronous device relations message sending >> from the host, if this message arrives to the guest after >> hv_send_resource_allocated() is called, the retry would fail. >> >> Fix the problem by moving retry to hv_pci_probe() and start the retry >> from hv_pci_query_relations() call. This will cause a device relations >> message to arrive to the guest synchronously; the guest would then be >> able to rebuild the child device structures before calling >> hv_send_resource_allocated(). >> >> Link: >> https://lore.kernel.org/linux-hyperv/20200727071731.18516-1-weh@microsoft.com/ >> Fixes: c81992e7f4aa ("PCI: hv: Retry PCI bus D0 entry on invalid device state") >> Signed-off-by: Wei Hu <weh@microsoft.com> >> [lorenzo.pieralisi@arm.com: fixed a comment and commit log] >> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> >> Reviewed-by: Michael Kelley <mikelley@microsoft.com> >> Signed-off-by: Sasha Levin <sashal@kernel.org> >> --- >> drivers/pci/controller/pci-hyperv.c | 71 +++++++++++++++-------------- >> 1 file changed, 37 insertions(+), 34 deletions(-) >> > >This patch came through three days ago, and I indicated then that we don't want >it backported to 5.8 and earlier.
Uh, I re-added it by mistake, sorry.
-- Thanks, Sasha
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