[PATCH v3 05/10] s390/pci: Restore IRQ unconditionally for the zPCI device

Farhan Ali
2025-09-11T18:33:18Z

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.

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.

Signed-off-by: Farhan Ali <alifm@linux.ibm.com>
---
arch/s390/include/asm/pci.h | 1 -
arch/s390/pci/pci_irq.c | 9 +--------
2 files changed, 1 insertion(+), 9 deletions(-)

diff --git a/arch/s390/include/asm/pci.h b/arch/s390/include/asm/pci.h
index 41f900f693d9..aed19a1aa9d7 100644
--- a/arch/s390/include/asm/pci.h
+++ b/arch/s390/include/asm/pci.h
@@ -145,7 +145,6 @@ struct zpci_dev {
u8 has_resources : 1;
u8 is_physfn : 1;
u8 util_str_avail : 1;
- u8 irqs_registered : 1;
u8 tid_avail : 1;
u8 rtr_avail : 1; /* Relaxed translation allowed */
unsigned int devfn; /* DEVFN part of the RID*/
diff --git a/arch/s390/pci/pci_irq.c b/arch/s390/pci/pci_irq.c
index 84482a921332..e73be96ce5fe 100644
--- 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 *zdev)
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_dev *zdev)
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_dev *pdev)
{
struct zpci_dev *zdev = to_zpci(pdev);

- if (!zdev->irqs_registered)
- zpci_set_irq(zdev);
+ zpci_set_irq(zdev);
return true;
}

--
2.43.0