On 6/6/2021 5:30 AM, Sandor Bodo-Merle wrote: > The interrupt affinity scheme used by this driver is incompatible with > multi-MSI as it implies moving the doorbell address to that of another MSI > group. This isn't possible for multi-MSI, as all the MSIs must have the > same doorbell address. As such it is restricted to systems with a single > CPU. > > Fixes: fc54bae28818 ("PCI: iproc: Allow allocation of multiple MSIs") > Reported-by: Marc Zyngier > Signed-off-by: Sandor Bodo-Merle > --- > drivers/pci/controller/pcie-iproc-msi.c | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) > > diff --git a/drivers/pci/controller/pcie-iproc-msi.c b/drivers/pci/controller/pcie-iproc-msi.c > index 557d93dcb3bc..81b4effeb130 100644 > --- a/drivers/pci/controller/pcie-iproc-msi.c > +++ b/drivers/pci/controller/pcie-iproc-msi.c > @@ -171,7 +171,7 @@ static struct irq_chip iproc_msi_irq_chip = { > > static struct msi_domain_info iproc_msi_domain_info = { > .flags = MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS | > - MSI_FLAG_MULTI_PCI_MSI | MSI_FLAG_PCI_MSIX, > + MSI_FLAG_PCI_MSIX, > .chip = &iproc_msi_irq_chip, > }; > > @@ -250,6 +250,9 @@ static int iproc_msi_irq_domain_alloc(struct irq_domain *domain, > struct iproc_msi *msi = domain->host_data; > int hwirq, i; > > + if (msi->nr_cpus > 1 && nr_irqs > 1) > + return -EINVAL; > + This should never happen since the framework would have guarded against this. But I guess it does not hurt to have the check here. > mutex_lock(&msi->bitmap_lock); > > /* > @@ -540,6 +543,9 @@ int iproc_msi_init(struct iproc_pcie *pcie, struct device_node *node) > mutex_init(&msi->bitmap_lock); > msi->nr_cpus = num_possible_cpus(); > > + if (msi->nr_cpus == 1) > + iproc_msi_domain_info.flags |= MSI_FLAG_MULTI_PCI_MSI; > + > msi->nr_irqs = of_irq_count(node); > if (!msi->nr_irqs) { > dev_err(pcie->dev, "found no MSI GIC interrupt\n"); > Looks fine to me. Thanks. Acked-by: Ray Jui