** Tags added: cscc
--
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:
Fix Released
Status in linux package in Ubuntu:
Fix Released
Status in linux source package in Artful:
Fix Released
Status in linux source package in Bionic:
Fix Released
Status in linux source package in Cosmic:
Fix Released
Bug description:
== SRU Justification ==
IBM is requesting this patch in Bionic and Artful to fix a regression. The
regression was introduced in v3.11-rc1. The patch fixes enabling bridge
MMIO windows. Commit 13a83eac373c was also cc'd to upstream stable, and
has already landed in Xenial via upstream stable updates.
== Fix ==
13a83eac373c ("powerpc/eeh: Fix enabling bridge MMIO windows")
== Regression Potential ==
Low. Limited to powerpc and fixes a current regression.
== Test Case ==
A test kernel was built with this patch and tested by the original bug
reporter.
The bug reporter states the test kernel resolved the bug.
== Comment: #0 - Breno Leitao <[email protected]>
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 : [email protected]
Unsubscribe : https://launchpad.net/~kernel-packages
More help : https://help.launchpad.net/ListHelp
