The following unhandled IRQ warning is seen during shutdown:
irq 16: nobody cared (try booting with the "irqpoll" option)
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.8.2-1.el7_UNSUPPORTED.x86_64 #1
Hardware name: Hewlett-Packard HP Z820 Workstation/158B, BIOS J63 v03.90 06/01/2016
0000000000000000 ffff88041f803e70 ffffffff81333bd5 ffff88041cb78200
ffff88041cb7829c ffff88041f803e98 ffffffff810d9465 ffff88041cb78200
0000000000000000 0000000000000028 ffff88041f803ed0 ffffffff810d97bf
Call Trace:
<IRQ> [<ffffffff81333bd5>] dump_stack+0x63/0x8e
[<ffffffff810d9465>] __report_bad_irq+0x35/0xd0
[<ffffffff810d97bf>] note_interrupt+0x20f/0x260
[<ffffffff810d6b35>] handle_irq_event_percpu+0x45/0x60
[<ffffffff810d6b7c>] handle_irq_event+0x2c/0x50
[<ffffffff810da31a>] handle_fasteoi_irq+0x8a/0x150
[<ffffffff8102edfb>] handle_irq+0xab/0x130
[<ffffffff81082391>] ? _local_bh_enable+0x21/0x50
[<ffffffff817064ad>] do_IRQ+0x4d/0xd0
[<ffffffff81704502>] common_interrupt+0x82/0x82
<EOI> [<ffffffff815d0181>] ? cpuidle_enter_state+0xc1/0x280
[<ffffffff815d0174>] ? cpuidle_enter_state+0xb4/0x280
[<ffffffff815d0377>] cpuidle_enter+0x17/0x20
[<ffffffff810bf660>] cpu_startup_entry+0x220/0x3a0
[<ffffffff816f6da7>] rest_init+0x77/0x80
[<ffffffff81d8e147>] start_kernel+0x495/0x4a2
[<ffffffff81d8daa0>] ? set_init_arg+0x55/0x55
[<ffffffff81d8d120>] ? early_idt_handler_array+0x120/0x120
[<ffffffff81d8d5d6>] x86_64_start_reservations+0x2a/0x2c
[<ffffffff81d8d715>] x86_64_start_kernel+0x13d/0x14c
pci_device_shutdown() is called on each PCI device, and does
if (drv && drv->shutdown)
drv->shutdown(pci_dev);
pci_msi_shutdown(pci_dev);
pci_msix_shutdown(pci_dev);
The pci_msi_shutdown() and pci_msix_shutdown() functions both call
pci_intx_for_msi() which enables the intx interrupt independent of the driver.
The driver still thinks it is using MSI/X and the result is the above stack
trace.
We have seen this at Red Hat on various drivers: nouveau, ahci, and pcieport
(so far). Google search for "unhandled irq 16" yields many results reporting
similar behavior during shutdown indicating that this problem is widespread.
I can cause this to happen on a "stable" system by adding a 3 second delay in
pci_device_shutdown() which causes the number of spurious interrupts to exceed
the 100000 limit and display the warning above. Also note that by adding the
3 second delay, NVIDIA devices with device ID 0x0FF* hit this problem 100% of
the time.
darcari noticed that removing the pci_intx_for_msi() call resulted in a
stable system. After further discussions with Myron and Alex, Alex came up
idea of keeping the intx disabled during shutdown implemented below.
----8<----
The following unhandled IRQ warning is seen during shutdown:
irq 16: nobody cared (try booting with the "irqpoll" option)
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.8.2-1.el7_UNSUPPORTED.x86_64 #1
Hardware name: Hewlett-Packard HP Z820 Workstation/158B, BIOS J63 v03.90 06/01/2016
0000000000000000 ffff88041f803e70 ffffffff81333bd5 ffff88041cb78200
ffff88041cb7829c ffff88041f803e98 ffffffff810d9465 ffff88041cb78200
0000000000000000 0000000000000028 ffff88041f803ed0 ffffffff810d97bf
Call Trace:
<IRQ> [<ffffffff81333bd5>] dump_stack+0x63/0x8e
[<ffffffff810d9465>] __report_bad_irq+0x35/0xd0
[<ffffffff810d97bf>] note_interrupt+0x20f/0x260
[<ffffffff810d6b35>] handle_irq_event_percpu+0x45/0x60
[<ffffffff810d6b7c>] handle_irq_event+0x2c/0x50
[<ffffffff810da31a>] handle_fasteoi_irq+0x8a/0x150
[<ffffffff8102edfb>] handle_irq+0xab/0x130
[<ffffffff81082391>] ? _local_bh_enable+0x21/0x50
[<ffffffff817064ad>] do_IRQ+0x4d/0xd0
[<ffffffff81704502>] common_interrupt+0x82/0x82
<EOI> [<ffffffff815d0181>] ? cpuidle_enter_state+0xc1/0x280
[<ffffffff815d0174>] ? cpuidle_enter_state+0xb4/0x280
[<ffffffff815d0377>] cpuidle_enter+0x17/0x20
[<ffffffff810bf660>] cpu_startup_entry+0x220/0x3a0
[<ffffffff816f6da7>] rest_init+0x77/0x80
[<ffffffff81d8e147>] start_kernel+0x495/0x4a2
[<ffffffff81d8daa0>] ? set_init_arg+0x55/0x55
[<ffffffff81d8d120>] ? early_idt_handler_array+0x120/0x120
[<ffffffff81d8d5d6>] x86_64_start_reservations+0x2a/0x2c
[<ffffffff81d8d715>] x86_64_start_kernel+0x13d/0x14c
This occurs because the pci_msi_shutdown() and pci_msix_shutdown() functions
enable the legacy intx interrupt even though the device and driver were not
configured for legacy intx.
This patch blocks the enabling of intx during system shutdown or reboot.
Signed-off-by: Prarit Bhargava <prarit@xxxxxxxxxx>
Cc: Alex Williamson <alex.williamson@xxxxxxxxxx>
Cc: David Arcari <darcari@xxxxxxxxxx>
Cc: Myron Stowe <mstowe@xxxxxxxxxx>
Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
---
drivers/pci/msi.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index bfdd0744b686..915cc29797f9 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -910,7 +910,8 @@ void pci_msi_shutdown(struct pci_dev *dev)
desc = first_pci_msi_entry(dev);
pci_msi_set_enable(dev, 0);
- pci_intx_for_msi(dev, 1);
+ if (system_state == SYSTEM_RUNNING || system_state == SYSTEM_BOOTING)
+ pci_intx_for_msi(dev, 1);
dev->msi_enabled = 0;
/* Return the device with MSI unmasked as initial states */
@@ -1024,7 +1025,8 @@ void pci_msix_shutdown(struct pci_dev *dev)
}
pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_ENABLE, 0);
- pci_intx_for_msi(dev, 1);
+ if (system_state == SYSTEM_RUNNING || system_state == SYSTEM_BOOTING)
+ pci_intx_for_msi(dev, 1);
dev->msix_enabled = 0;
pcibios_alloc_irq(dev);
}
--
1.7.9.3
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