Re: [PATCH v2 2/2] s390/pci: Extend device lock to cover zpci_report_status()

[Niklas Schnelle <schnelle@linux.ibm.com>]

On Wed, 2026-08-19 at 14:30 -0700, Farhan Ali wrote:
> On 8/19/2026 2:58 AM, Niklas Schnelle wrote:
> > As zpci_report_status() accesses the device's driver the device lock
> > needs to be held. Extend the critical section to cover the
> > zpci_report_status() call.
> > 
> > Cc: stable@vger.kernel.org
> > Fixes: 4ec6054e7321 ("s390/pci: Report PCI error recovery results via SCLP")
> > Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
> > ---
> >   arch/s390/pci/pci_event.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/arch/s390/pci/pci_event.c b/arch/s390/pci/pci_event.c
> > index 839bd91c056e..48c150d6ba81 100644
> > --- a/arch/s390/pci/pci_event.c
> > +++ b/arch/s390/pci/pci_event.c
> > @@ -256,8 +256,8 @@ static pci_ers_result_t zpci_event_attempt_error_recovery(struct pci_dev *pdev)
> >   		driver->err_handler->resume(pdev);
> >   	pci_uevent_ers(pdev, PCI_ERS_RESULT_RECOVERED);
> >   out_unlock:
> > -	device_unlock(&pdev->dev);
> >   	zpci_report_status(zdev, "recovery", status_str);
> > +	device_unlock(&pdev->dev);
> >   
> >   	return ers_res;
> >   }
> 
> AFAICT this change is correct, but should we also add a lockdep_assert 
> in zpci_report_status()? Since this is the only placed its called, it 
> maybe fine as is. I just fear that we could miss on getting the lock if 
> we were to re-use zpci_report_status().
> 
> Either way
> Reviewed-by: Farhan Ali<alifm@linux.ibm.com>

Was pondering that as well. I was on the edge so left it out but since
you're mentioning it too I'll add it and send a v3 with that plus all
the R-bs.

Thanks,
Niklas