[PATCH kernel v3] powerpc/pci: Fix broken INTx configuration via OF

[Bjorn Helgaas]

On Fri, Feb 09, 2018 at 12:07:41PM -0600, Bjorn Helgaas wrote:
> On Fri, Feb 09, 2018 at 05:23:58PM +1100, Alexey Kardashevskiy wrote:
> > Commit 59f47eff03a0 ("powerpc/pci: Use of_irq_parse_and_map_pci() helper")
> > replaced of_irq_parse_pci() + irq_create_of_mapping() with
> > of_irq_parse_and_map_pci() but this change lost virq returned by
> > irq_create_of_mapping() so virq remained zero causing INTx
> > misconfiguration.
> > 
> > This fixes pci_read_irq_line() not to loose a virq returned by
> > of_irq_parse_and_map_pci().
> 
> s/not to loose a/to not lose the/
> 
> > Fixes: 59f47eff03a0 "powerpc/pci: Use of_irq_parse_and_map_pci() helper"
> > Signed-off-by: Alexey Kardashevskiy <aik at ozlabs.ru>
> 
> I'm fine with this version.
> 
> Since you started applying a previous version, Michael, I'll assume
> you will handle this unless you tell me otherwise.  One way or another
> it would be good to get this in before -rc1.

I went ahead and applied this and asked Linus to pull it.

> > ---
> > Changes:
> > v3:
> > * change virq from unsigned to int as of_irq_parse_and_map_pci returns int
> > and even though it only returns non-negative values now, this may change
> > in the future
> > 
> > v2:
> > * changed the condition from <=0 to !=0 as by design
> > of_irq_parse_and_map_pci() can only return 0 for an error and virq>0.
> > ---
> >  arch/powerpc/kernel/pci-common.c | 5 +++--
> >  1 file changed, 3 insertions(+), 2 deletions(-)
> > 
> > diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c
> > index ae2ede4..446c796 100644
> > --- a/arch/powerpc/kernel/pci-common.c
> > +++ b/arch/powerpc/kernel/pci-common.c
> > @@ -362,7 +362,7 @@ struct pci_controller* pci_find_hose_for_OF_device(struct device_node* node)
> >   */
> >  static int pci_read_irq_line(struct pci_dev *pci_dev)
> >  {
> > -	unsigned int virq = 0;
> > +	int virq;
> >  
> >  	pr_debug("PCI: Try to map irq for %s...\n", pci_name(pci_dev));
> >  
> > @@ -370,7 +370,8 @@ static int pci_read_irq_line(struct pci_dev *pci_dev)
> >  	memset(&oirq, 0xff, sizeof(oirq));
> >  #endif
> >  	/* Try to get a mapping from the device-tree */
> > -	if (!of_irq_parse_and_map_pci(pci_dev, 0, 0)) {
> > +	virq = of_irq_parse_and_map_pci(pci_dev, 0, 0);
> > +	if (virq <= 0) {
> >  		u8 line, pin;
> >  
> >  		/* If that fails, lets fallback to what is in the config
> > -- 
> > 2.11.0
> >