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Prarit Bhargava authored
The pci_bus_type .shutdown method, pci_device_shutdown(), is called from device_shutdown() in the kernel restart and shutdown paths. Previously, pci_device_shutdown() called pci_msi_shutdown() and pci_msix_shutdown(). This disables MSI and MSI-X, which causes the device to fall back to raising interrupts via INTx. But the driver is still bound to the device, it doesn't know about this change, and it likely doesn't have an INTx handler, so these INTx interrupts cause "nobody cared" warnings like this: 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/ ... The MSI disabling code was added by d52877c7 ("pci/irq: let pci_device_shutdown to call pci_msi_shutdown v2") because a driver left MSI enabled and kdump failed because the kexeced kernel wasn't prepared to receive the MSI interrupts. Subsequent commits 1851617c ("PCI/MSI: Disable MSI at enumeration even if kernel doesn't support MSI") and e80e7edc ("PCI/MSI: Initialize MSI capability for all architectures") changed the kexeced kernel to disable all MSIs itself so it no longer depends on the crashed kernel to clean up after itself. Stop disabling MSI/MSI-X in pci_device_shutdown(). This resolves the "nobody cared" unhandled IRQ issue above. It also allows PCI serial devices, which may rely on the MSI interrupts, to continue outputting messages during reboot/shutdown. [bhelgaas: changelog, drop pci_msi_shutdown() and pci_msix_shutdown() calls altogether] Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=187351Signed-off-by:
Prarit Bhargava <prarit@redhat.com> Signed-off-by:
Bjorn Helgaas <bhelgaas@google.com> CC: Alex Williamson <alex.williamson@redhat.com> CC: David Arcari <darcari@redhat.com> CC: Myron Stowe <mstowe@redhat.com> CC: Lukas Wunner <lukas@wunner.de> CC: Keith Busch <keith.busch@intel.com> CC: Mika Westerberg <mika.westerberg@linux.intel.com>
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