Hi Shawn, I'd suggest to change the designware by dwc on the patch title. On 25/10/2018 03:47, Shawn Lin wrote: > On some platform, external MSI domain is using instead of the one > created by designware driver. For instance, if using GIC-V3-ITS > as a MSI domain, we only need set msi-map in the devicetree but > never need any bit in the designware driver to handle MSI stuff. > So skip allocating its own MSI domain for that case. > > Signed-off-by: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx> > > --- > > drivers/pci/controller/dwc/pcie-designware-host.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c > index 29a0575..39254b1 100644 > --- a/drivers/pci/controller/dwc/pcie-designware-host.c > +++ b/drivers/pci/controller/dwc/pcie-designware-host.c > @@ -278,6 +278,10 @@ int dw_pcie_allocate_domains(struct pcie_port *pp) > return -ENOMEM; > } > > + /* Rely on the external MSI domain */ > + if (device_property_read_bool(dev, "msi-map")) > + return 0; > + I would suggest to read this property only in the init of the host and configuring it in a Boolean variable to be created in the pp structure and use it to verify the feature presence or not. > pp->msi_domain = pci_msi_create_irq_domain(fwnode, > &dw_pcie_msi_domain_info, > pp->irq_domain); > @@ -433,7 +437,8 @@ int dw_pcie_host_init(struct pcie_port *pp) > if (ret) > pci->num_viewport = 2; > > - if (IS_ENABLED(CONFIG_PCI_MSI)) { > + if (IS_ENABLED(CONFIG_PCI_MSI) && > + !device_property_read_bool(dev, "msi-map")) { You could use the previous boolean variable here also. > /* > * If a specific SoC driver needs to change the > * default number of vectors, it needs to implement > You should protect the dw_pcie_free_msi(), since it uses the pp->msi_domain and pp->msi_irq also, maybe using the boolean variable also. Regards, Gustavo