Re: [PATCH v1 1/6] s390/pci: Restore airq unconditionally for the zPCI device

[Farhan Ali]

On 8/14/2025 4:32 AM, Niklas Schnelle wrote:
> On Wed, 2025-08-13 at 10:08 -0700, Farhan Ali wrote:
> > 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 (zpci_hot_reset_device),
> > the airq setup of the device will need to be restored. Since we
> > are no longer calling zpci_clear_airq() in the reset path, we should
> > restore the airq for device unconditionally.
> >
> > Signed-off-by: Farhan Ali <alifm@xxxxxxxxxxxxx>
> > ---
> >   arch/s390/pci/pci_irq.c | 3 +--
> >   1 file changed, 1 insertion(+), 2 deletions(-)
> >
> > diff --git a/arch/s390/pci/pci_irq.c b/arch/s390/pci/pci_irq.c
> > index 84482a921332..8b5493f0dee0 100644
> > --- a/arch/s390/pci/pci_irq.c
> > +++ b/arch/s390/pci/pci_irq.c
> > @@ -427,8 +427,7 @@ 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;
> >   }
> >   
> This would make zdev->irqs_registered effectively without function so
> the patch should remove that field from struct zpci_dev and
> zpci_set_irq()/zpci_clear_irq(). Alternatively you could also clear
> zdev->irqs_registed in zpci_disable_device(). I think the former is
> cleaner though.
>
> Thanks,
> Niklas
Yeah agreed, will remove the irqs_registered from zdev as its not needed 
anymore.

Thanks
Farhan