If U-Boot does not have any I/O resource for assignment then disable I/O forwarding in PCI bridge autoconfiguration code. Default initial state of PCI bridge IO registers is unspecified, therefore they can be in enabled if U-Boot does not touch them.
Signed-off-by: Pali Rohár pali@kernel.org --- drivers/pci/pci_auto.c | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/drivers/pci/pci_auto.c b/drivers/pci/pci_auto.c index 7e6ee54be087..6e5ed194f247 100644 --- a/drivers/pci/pci_auto.c +++ b/drivers/pci/pci_auto.c @@ -265,6 +265,14 @@ void dm_pciauto_prescan_setup_bridge(struct udevice *dev, int sub_bus) (pci_io->bus_lower & 0xffff0000) >> 16);
cmdstat |= PCI_COMMAND_IO; + } else { + /* Disable I/O if unsupported */ + dm_pci_write_config8(dev, PCI_IO_BASE, 0xf0 | io_32); + dm_pci_write_config8(dev, PCI_IO_LIMIT, 0x0 | io_32); + if (io_32 == PCI_IO_RANGE_TYPE_32) { + dm_pci_write_config16(dev, PCI_IO_BASE_UPPER16, 0x0); + dm_pci_write_config16(dev, PCI_IO_LIMIT_UPPER16, 0x0); + } }
/* Enable memory and I/O accesses, enable bus master */