Farhan AliandGreg Kroah-Hartman 6e43d5f0e5 s390/pci: Restore IRQ unconditionally for the zPCI device ...

[ Upstream commit b45873c3f0 ]

Commit c1e18c17bd ("s390/pci: add zpci_set_irq()/zpci_clear_irq()"),
introduced the zpci_set_irq() and zpci_clear_irq(), to be used while
resetting a zPCI device.

Commit da995d538d ("s390/pci: implement reset_slot for hotplug
slot"), mentions zpci_clear_irq() being called in the path for
zpci_hot_reset_device().  But that is not the case anymore and these
functions are not called outside of this file. Instead
zpci_hot_reset_device() relies on zpci_disable_device() also clearing
the IRQs, but misses to reset the zdev->irqs_registered flag.

However after a CLP disable/enable reset, the device's IRQ are
unregistered, but the flag zdev->irq_registered does not get cleared. It
creates an inconsistent state and so arch_restore_msi_irqs() doesn't
correctly restore the device's IRQ. This becomes a problem when a PCI
driver tries to restore the state of the device through
pci_restore_state(). Restore IRQ unconditionally for the device and remove
the irq_registered flag as its redundant.

Fixes: c1e18c17bd ("s390/pci: add zpci_set_irq()/zpci_clear_irq()")
Cc: stable@vger.kernnel.org
Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Farhan Ali <alifm@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
[ adjusted bitfield context ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2025-11-24 10:29:16 +01:00

..

asm

s390/pci: Restore IRQ unconditionally for the zPCI device

2025-11-24 10:29:16 +01:00

uapi/asm

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