Change in ...coreboot[master]: src/mb/pcengines/apu2/mainboard.c: Fix retrieving serial number

[Michał Żygowski (Code Review)]

Michał Żygowski has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/29842

Change subject: src/mb/pcengines/apu2/mainboard.c: Fix retrieving serial number
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src/mb/pcengines/apu2/mainboard.c: Fix retrieving serial number

Handle situation when first NIC is not BDF 1:0.0. The PCI enumeration
is different when a external PCIe device is connected to mPCIe2 slot
which is routed to first PCIe bridge. The first NIC is then assigned
BDF 2:0.0, because it is connected to the second PCIe bridge.

Add a check for vendor ID and device ID of the NIC, before reading
MAC address and calculating serial number.

Signed-off-by: Michał Żygowski 
Change-Id: I9f89a6f3cd0c23a2d2924e587338f69c260b12f8
---
M src/mainboard/pcengines/apu2/mainboard.c
1 file changed, 30 insertions(+), 2 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/42/29842/1

diff --git a/src/mainboard/pcengines/apu2/mainboard.c b/src/mainboard/pcengines/apu2/mainboard.c
index 35385c2..f54c4a0 100644
--- a/src/mainboard/pcengines/apu2/mainboard.c
+++ b/src/mainboard/pcengines/apu2/mainboard.c
@@ -19,6 +19,7 @@
 #include <device/device.h>
 #include <device/pci.h>
 #include <device/pci_def.h>
+#
 #include <southbridge/amd/pi/hudson/hudson.h>
 #include <southbridge/amd/pi/hudson/pci_devs.h>
 #include <southbridge/amd/pi/hudson/amd_pci_int_defs.h>
@@ -197,11 +198,38 @@
    struct device *nic_dev;
    uintptr_t bar10;
    u32 mac_addr = 0;
+	u16 vendor_id, device_id;
    int i;

nic_dev = dev_find_slot(1, PCI_DEVFN(0, 0));
-	if ((serial[0] != 0) || !nic_dev)
-		return serial;
+	/*
+	 * Check if we really have found first NIC. In case we have PCIe module
+	 * connected to mPCIe2 slot, BDF 1:0.0 may not be a NIC, because mPCIe2
+	 * slot is routed to the very first PCIe bridge and the first NIC is
+	 * connected to the second PCIe bridge.
+	 */
+	if (!serial || !nic_dev)
+		return -1;
+	vendor_id = pci_read_config16(nic_dev, 0x0);
+	device_id = pci_read_config16(nic_dev, 0x2);
+
+	/*
+	 * apu boards have Intel NICs. If vendor ID does not match, it means
+	 * that something is connected to mPCIe2 slot. Look on BDF 2:0.0.
+	 */
+	if (vendor_id != PCI_VENDOR_ID_INTEL) {
+		nic_dev = dev_find_slot(2, PCI_DEVFN(0, 0));
+		if (!nic_dev)
+			return -1;
+		vendor_id = pci_read_config16(nic_dev, 0x0);
+		device_id = pci_read_config16(nic_dev, 0x2);
+		if (vendor_id != PCI_VENDOR_ID_INTEL)
+			return -1;
+	}
+
+	/* Handle both hardware options: i210 and i211 NICs */
+	if ((device_id != 0x1537) && (device_id != 0x157b))
+		return -1;

/* Read in the last 3 bytes of NIC's MAC address. */
    bar10 = pci_read_config32(nic_dev, 0x10);