[PATCH 2/5] pci: Skip configuring invalid P2P bridge devices

[Pali Rohár]

Function dm_pci_hose_probe_bus() expects that bus is valid PCI device with
Bridge header type (0x01). So add check before touching PCI config space to
prevent misconfiguring some non-standard device.

Signed-off-by: Pali Rohár <pali at kernel.org>
---
 drivers/pci/pci-uclass.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/pci/pci-uclass.c b/drivers/pci/pci-uclass.c
index 044babee164f..5da3515f5f25 100644
--- a/drivers/pci/pci-uclass.c
+++ b/drivers/pci/pci-uclass.c
@@ -627,6 +627,7 @@ int pci_generic_mmap_read_config(
 
 int dm_pci_hose_probe_bus(struct udevice *bus)
 {
+	u8 header_type;
 	int sub_bus;
 	int ret;
 	int ea_pos;
@@ -634,6 +635,14 @@ int dm_pci_hose_probe_bus(struct udevice *bus)
 
 	debug("%s\n", __func__);
 
+	dm_pci_read_config8(bus, PCI_HEADER_TYPE, &header_type);
+	header_type &= 0x7f;
+	if (header_type != PCI_HEADER_TYPE_BRIDGE) {
+		debug("%s: Skipping PCI device %d with Non-Bridge Header Type 0x%x\n",
+		      __func__, PCI_DEV(dm_pci_get_bdf(bus)), header_type);
+		return log_msg_ret("probe", -EINVAL);
+	}
+
 	ea_pos = dm_pci_find_capability(bus, PCI_CAP_ID_EA);
 	if (ea_pos) {
 		dm_pci_read_config8(bus, ea_pos + sizeof(u32) + sizeof(u8),
-- 
2.20.1