RE: [PATCH v2] PCI: xilinx-nwl: Fix Multi MSI data programming

[Bharat Kumar Gogada]

> Subject: Re: [PATCH v2] PCI: xilinx-nwl: Fix Multi MSI data programming
> 
> On Mon, 11 Mar 2019 at 12:46, Bharat Kumar Gogada
> <bharat.kumar.gogada@xxxxxxxxxx> wrote:
> >
> > The current Multi MSI data programming fails if multiple end points
> > requesting MSI and multi MSI are connected with switch, i.e the
> > current multi MSI data being given is not considering the number of
> > vectors being requested in case of multi MSI.
> > Due to this if multiple end points are connected and requesting MSI
> > and multi MSI combination, the multi MSI data is ending up using wrong
> > MSI data, which might be used by different device.
> >
> > Fix Multi MSI data programming with required alignment by using number
> > of vectors being requested.
> >
> > Fixes: ab597d35ef11 ("PCI: xilinx-nwl: Add support for Xilinx NWL PCIe
> > Host Controller")
> > Signed-off-by: Bharat Kumar Gogada <bharat.kumar.gogada@xxxxxxxxxx>
> > ---
> > V2:
> >  - Added more description of fix
> > ---
> >  drivers/pci/controller/pcie-xilinx-nwl.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/pci/controller/pcie-xilinx-nwl.c
> > b/drivers/pci/controller/pcie-xilinx-nwl.c
> > index 81538d7..36669c5 100644
> > --- a/drivers/pci/controller/pcie-xilinx-nwl.c
> > +++ b/drivers/pci/controller/pcie-xilinx-nwl.c
> > @@ -484,7 +484,7 @@ static int nwl_irq_domain_alloc(struct irq_domain
> > *domain, unsigned int virq,
> >
> >         mutex_lock(&msi->lock);
> >         bit = bitmap_find_next_zero_area(msi->bitmap, INT_PCI_MSI_NR, 0,
> > -                                        nr_irqs, 0);
> > +                                        nr_irqs, nr_irqs - 1);
> 
> Are you sure nr_irqs is guaranteed to be a power of 2?
Hi Ard, Thanks for your time.
After checking other source codes its not guaranteed, will add extra check and resend patch.

Regards,
Bharat
> 
> >         if (bit >= INT_PCI_MSI_NR) {
> >                 mutex_unlock(&msi->lock);
> >                 return -ENOSPC;
> > --
> > 2.7.4
> >
> >
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