On Thu, 2019-10-03 at 13:39 -0700, Alexander Duyck wrote: > On Thu, Oct 3, 2019 at 11:51 AM David Z. Dai <z...@linux.vnet.ibm.com> wrote: > > > > On Thu, 2019-10-03 at 10:39 -0700, Alexander Duyck wrote: > > > On Thu, Oct 3, 2019 at 9:59 AM David Dai <z...@linux.vnet.ibm.com> wrote: > > > > > > > > We see the behavior when EEH e1000e adapter detects io permanent > > > > failure, > > > > it will crash kernel with this stack: > > > > EEH: Beginning: 'error_detected(permanent failure)' > > > > EEH: PE#900000 (PCI 0115:90:00.1): Invoking > > > > e1000e->error_detected(permanent failure) > > > > EEH: PE#900000 (PCI 0115:90:00.1): e1000e driver reports: 'disconnect' > > > > EEH: PE#900000 (PCI 0115:90:00.0): Invoking > > > > e1000e->error_detected(permanent failure) > > > > EEH: PE#900000 (PCI 0115:90:00.0): e1000e driver reports: 'disconnect' > > > > EEH: Finished:'error_detected(permanent failure)' > > > > Oops: Exception in kernel mode, sig: 5 [#1] > > > > NIP [c0000000007b1be0] free_msi_irqs+0xa0/0x280 > > > > LR [c0000000007b1bd0] free_msi_irqs+0x90/0x280 > > > > Call Trace: > > > > [c0000004f491ba10] [c0000000007b1bd0] free_msi_irqs+0x90/0x280 > > > > (unreliable) > > > > [c0000004f491ba70] [c0000000007b260c] pci_disable_msi+0x13c/0x180 > > > > [c0000004f491bab0] [d0000000046381ac] e1000_remove+0x234/0x2a0 [e1000e] > > > > [c0000004f491baf0] [c000000000783cec] pci_device_remove+0x6c/0x120 > > > > [c0000004f491bb30] [c00000000088da6c] > > > > device_release_driver_internal+0x2bc/0x3f0 > > > > [c0000004f491bb80] [c00000000076f5a8] > > > > pci_stop_and_remove_bus_device+0xb8/0x110 > > > > [c0000004f491bbc0] [c00000000006e890] pci_hp_remove_devices+0x90/0x130 > > > > [c0000004f491bc50] [c00000000004ad34] > > > > eeh_handle_normal_event+0x1d4/0x660 > > > > [c0000004f491bd10] [c00000000004bf10] eeh_event_handler+0x1c0/0x1e0 > > > > [c0000004f491bdc0] [c00000000017c4ac] kthread+0x1ac/0x1c0 > > > > [c0000004f491be30] [c00000000000b75c] ret_from_kernel_thread+0x5c/0x80 > > > > > > > > Basically the e1000e irqs haven't been freed at the time eeh is trying > > > > to > > > > remove the the e1000e device. > > > > Need to make sure when e1000e_close is called to bring down the NIC, > > > > if adapter error_state is pci_channel_io_perm_failure, it should also > > > > bring down the link and free irqs. > > > > > > > > Reported-by: Morumuri Srivalli <smoru...@in.ibm.com> > > > > Signed-off-by: David Dai <z...@linux.vnet.ibm.com> > > > > --- > > > > drivers/net/ethernet/intel/e1000e/netdev.c | 3 ++- > > > > 1 files changed, 2 insertions(+), 1 deletions(-) > > > > > > > > diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c > > > > b/drivers/net/ethernet/intel/e1000e/netdev.c > > > > index d7d56e4..cf618e1 100644 > > > > --- a/drivers/net/ethernet/intel/e1000e/netdev.c > > > > +++ b/drivers/net/ethernet/intel/e1000e/netdev.c > > > > @@ -4715,7 +4715,8 @@ int e1000e_close(struct net_device *netdev) > > > > > > > > pm_runtime_get_sync(&pdev->dev); > > > > > > > > - if (!test_bit(__E1000_DOWN, &adapter->state)) { > > > > + if (!test_bit(__E1000_DOWN, &adapter->state) || > > > > + (adapter->pdev->error_state == > > > > pci_channel_io_perm_failure)) { > > > > e1000e_down(adapter, true); > > > > e1000_free_irq(adapter); > > > > > > It seems like the issue is the fact that e1000_io_error_detected is > > > calling e1000e_down without the e1000_free_irq() bit. Instead of doing > > > this couldn't you simply add the following to e1000_is_slot_reset in > > > the "result = PCI_ERS_RESULT_DISCONNECT" case: > > > if (netif_running(netdev) > > > e1000_free_irq(adapter); > > > > > > Alternatively we could look at freeing and reallocating the IRQs in > > > the event of an error like we do for the e1000e_pm_freeze and > > > e1000e_pm_thaw cases. That might make more sense since we are dealing > > > with an error we might want to free and reallocate the IRQ resources > > > assigned to the device. > > > > > > Thanks. > > > > > > - Alex > > > > Thanks for the quick reply and comment! > > Looked the e1000_io_slot_reset() routine: > > err = pci_enable_device_mem(pdev); > > if (err) { > > dev_err(&pdev->dev, > > "Cannot re-enable PCI device after reset.\n"); > > result = PCI_ERS_RESULT_DISCONNECT; > > } else { > > I didn't see log message "Cannot re-enable PCI device after reset" at > > the time of crash. > > > > I can still apply the same logic in e1000_io_error_detected() routine: > > if (state == pci_channel_io_perm_failure) { > > + if (netif_running(netdev)) > > + e1000_free_irq(adapter); > > return PCI_ERS_RESULT_DISCONNECT; > > } > > Will test this once the test hardware is available again. > > Are you sure this is the path you are hitting? Things aren't adding up. > > I thought the issue was that the interface for the error handling was > calling e1000e_down() but not freeing the IRQs? In the path where you > are adding your code I don't see how the __E1000_DOWN would have been > set? > > - Alex We see the same stack every time the crash is triggered.
My understanding is not that the interface for the error handling was calling e1000e_down() but not freeing IRQs. In our case, on powerpc , if injecting eeh errors to reach preset threshold value, it will be forced to be offline permanently. In e1000e_close() to bring down link, the check: "if (! test_bit(__E1000_DOWN, &adapter->state))" is false, so e1000e_down() and e1000_free_irq() are both not called. IRQs are not freed. When e1000_remove() is called, it sees IRQs are not free, hence crash the kernel. This is the reason I have the original proposed patch to add an extra check in e1000e_close(). For the 2nd change in e1000_io_error_detected() routine, I haven't tested it yet. Pardon me if causing any confusion, and Thanks for your time again! - David