The bridge logic at slot 0 only supports reads up to 0x40 and the rest of the PCI configuration space for this slot is marked as reserved in the manual. Trying a read from offset 0x100 is producing an error from the bridge. With error interrupts enabled, the following is printed: pci-rcar-gen2 ee0d0000.pci: error irq: status 00000014 Signed-off-by: Ben Dooks <ben.dooks@xxxxxxxxxxxxxxx> --- Cc: Valentine Barshak <valentine.barshak@xxxxxxxxxxxxxxxxxx> Cc: Simon Horman <horms@xxxxxxxxxxxx> Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> Cc: linux-pci@xxxxxxxxxxxxxxx Cc: linux-sh@xxxxxxxxxxxxxxx --- drivers/pci/host/pci-rcar-gen2.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/pci/host/pci-rcar-gen2.c b/drivers/pci/host/pci-rcar-gen2.c index 01ba069..42f0105 100644 --- a/drivers/pci/host/pci-rcar-gen2.c +++ b/drivers/pci/host/pci-rcar-gen2.c @@ -119,6 +119,10 @@ static void __iomem *rcar_pci_cfg_base(struct pci_bus *bus, unsigned int devfn, if (slot > 2) return NULL; + /* bridge logic only has registers to 0x40 */ + if (slot == 0x0 && where >= 0x40) + return NULL; + val = slot ? RCAR_AHBPCI_WIN1_DEVICE | RCAR_AHBPCI_WIN_CTR_CFG : RCAR_AHBPCI_WIN1_HOST | RCAR_AHBPCI_WIN_CTR_CFG; -- 1.8.5.2 -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html