** Tags removed: targetmilestone-inin--- ** Tags added: targetmilestone-inin1804
-- 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 <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
