On Wed, 2018-04-11 at 03:37:58 UTC, Michael Neuling wrote: > 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. > > Reported-by: Pridhiviraj Paidipeddi <ppaid...@linux.vnet.ibm.com> > Signed-off-by: Michael Neuling <mi...@neuling.org> > Cc: sta...@vger.kernel.org > Acked-by: Russell Currey <rus...@russell.cc>
Applied to powerpc fixes, thanks. https://git.kernel.org/powerpc/c/13a83eac373c49c0a081cbcd137e79 cheers
