Public bug reported:
== Comment: #0 - Breno Leitao <bren...@br.ibm.com>
On boot we save the configuration space of PCIe bridges. We do this so
when we get an EEH event and everything gets reset that we can restore
them.
Unfortunately we save this state before we've enabled the MMIO space
on the bridges. Hence if we have to reset the bridge when we come back
MMIO is not enabled and we end up taking an PE freeze when the driver
starts accessing again.
This patch forces the memory/MMIO and bus mastering on when restoring
bridges on EEH. Ideally we'd do this correctly by saving the
configuration space writes later, but that will have to come later in
a larger EEH rewrite. For now we have this simple fix.
The original bug can be triggered on a boston machine by doing:
echo 0x8000000000000000 > /sys/kernel/debug/powerpc/PCI0001/err_injct_outbound
On boston, this PHB has a PCIe switch on it. Without this patch,
you'll see two EEH events, 1 expected and 1 the failure we are fixing
here. The second EEH event causes the anything under the PHB to
disappear (i.e. the i40e eth).
With this patch, only 1 EEH event occurs and devices properly recover.
This is commit id 13a83eac373c49c0a081cbcd137e79210fe78acd and should be
part of Ubuntu 18.04 kernel.
** Affects: ubuntu-power-systems
Importance: High
Assignee: Canonical Kernel Team (canonical-kernel-team)
Status: Triaged
** Affects: linux (Ubuntu)
Importance: Undecided
Assignee: Ubuntu on IBM Power Systems Bug Triage (ubuntu-power-triage)
Status: New
** Tags: architecture-ppc64le bugnameltc-167852 severity-high
targetmilestone-inin--- triage-g
** Tags added: architecture-ppc64le bugnameltc-167852 severity-high
targetmilestone-inin---
** Changed in: ubuntu
Assignee: (unassigned) => Ubuntu on IBM Power Systems Bug Triage
(ubuntu-power-triage)
** Package changed: ubuntu => linux (Ubuntu)
--
You received this bug notification because you are a member of Kernel
Packages, which is subscribed to linux in Ubuntu.
https://bugs.launchpad.net/bugs/1771344
Title:
Fix enabling bridge MMIO windows
Status in The Ubuntu-power-systems project:
Triaged
Status in linux package in Ubuntu:
New
Bug description:
== Comment: #0 - Breno Leitao <bren...@br.ibm.com>
On boot we save the configuration space of PCIe bridges. We do this so
when we get an EEH event and everything gets reset that we can restore
them.
Unfortunately we save this state before we've enabled the MMIO space
on the bridges. Hence if we have to reset the bridge when we come back
MMIO is not enabled and we end up taking an PE freeze when the driver
starts accessing again.
This patch forces the memory/MMIO and bus mastering on when restoring
bridges on EEH. Ideally we'd do this correctly by saving the
configuration space writes later, but that will have to come later in
a larger EEH rewrite. For now we have this simple fix.
The original bug can be triggered on a boston machine by doing:
echo 0x8000000000000000 >
/sys/kernel/debug/powerpc/PCI0001/err_injct_outbound
On boston, this PHB has a PCIe switch on it. Without this patch,
you'll see two EEH events, 1 expected and 1 the failure we are fixing
here. The second EEH event causes the anything under the PHB to
disappear (i.e. the i40e eth).
With this patch, only 1 EEH event occurs and devices properly recover.
This is commit id 13a83eac373c49c0a081cbcd137e79210fe78acd and should
be part of Ubuntu 18.04 kernel.
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu-power-systems/+bug/1771344/+subscriptions
--
Mailing list: https://launchpad.net/~kernel-packages
Post to : kernel-packages@lists.launchpad.net
Unsubscribe : https://launchpad.net/~kernel-packages
More help : https://help.launchpad.net/ListHelp
