6.1-stable review patch. If anyone has any objections, please let me know.
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From: Farhan Ali alifm@linux.ibm.com
[ Upstream commit b45873c3f09153d1ad9b3a7bf9e5c0b0387fd2ea ]
Commit c1e18c17bda6 ("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 da995d538d3a ("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: c1e18c17bda6 ("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 --- arch/s390/include/asm/pci.h | 1 - arch/s390/pci/pci_irq.c | 9 +-------- 2 files changed, 1 insertion(+), 9 deletions(-)
--- a/arch/s390/include/asm/pci.h +++ b/arch/s390/include/asm/pci.h @@ -136,7 +136,6 @@ struct zpci_dev { u8 has_resources : 1; u8 is_physfn : 1; u8 util_str_avail : 1; - u8 irqs_registered : 1; u8 reserved : 2; unsigned int devfn; /* DEVFN part of the RID*/
--- a/arch/s390/pci/pci_irq.c +++ b/arch/s390/pci/pci_irq.c @@ -107,9 +107,6 @@ static int zpci_set_irq(struct zpci_dev else rc = zpci_set_airq(zdev);
- if (!rc) - zdev->irqs_registered = 1; - return rc; }
@@ -123,9 +120,6 @@ static int zpci_clear_irq(struct zpci_de else rc = zpci_clear_airq(zdev);
- if (!rc) - zdev->irqs_registered = 0; - return rc; }
@@ -427,8 +421,7 @@ bool arch_restore_msi_irqs(struct pci_de { struct zpci_dev *zdev = to_zpci(pdev);
- if (!zdev->irqs_registered) - zpci_set_irq(zdev); + zpci_set_irq(zdev); return true; }