From: Greg Kroah-Hartman <gre...@linuxfoundation.org> Sent: Thursday, August 20, 2020 2:20 AM > > From: Wei Hu <w...@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-...@microsoft.com/ > Fixes: c81992e7f4aa ("PCI: hv: Retry PCI bus D0 entry on invalid device > state") > Signed-off-by: Wei Hu <w...@microsoft.com> > [lorenzo.pieral...@arm.com: fixed a comment and commit log] > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieral...@arm.com> > Reviewed-by: Michael Kelley <mikel...@microsoft.com> > Signed-off-by: Sasha Levin <sas...@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. Michael
