[BPI-R64] Pcie link not working at gen 2 speed

Banana Pi BPI-R4/BPI-R3 Mini/BPI-R3/BPI-R64/BPI-R2 OpenWRT
1

I use openwrt compiled from master, at slot 1 I have a mt7615 wifi card, slot 2 has a rtl8125 gbe controller. but, annoying: pcie gen 2 isn’t activated:

root@apbureau:~$ lspci -tv
-[0000:00]---00.0-[01-04]----00.0-[02-04]--+-03.0-[03]----00.0  Realtek Semiconductor Co., Ltd. RTL8125 2.5GbE Controller
                                       \-07.0-[04]----00.0  Realtek Semiconductor Co., Ltd. RTL8125 2.5GbE Controller
-[0001:00]---01.0-[01]----00.0  MEDIATEK Corp. MT7615E 802.11ac PCI Express Wireless Network Adapter
root@apbureau:$ dmesg | grep limited
[    1.460079] pci 0000:01:00.0: 2.000 Gb/s available PCIe bandwidth, limited by 2.5 GT/s PCIe x1 link at 0000:00:00.0 (capable of 4.000 Gb/s with 5.0 GT/s PCIe x1 link)
[    2.853448] pci 0001:01:00.0: 2.000 Gb/s available PCIe bandwidth, limited by 2.5 GT/s PCIe x1 link at 0001:00:01.0 (capable of 4.000 Gb/s with 5.0 GT/s PCIe x1 link)
root@apbureau:~#

Why? the specs show a gen 2 compatibility, why would it slow down to gen1?

2

Which kernel and which image?

3

Origin/master on github, kernel 5.15.116 EDIT: using bpi-r64, openwrt master branch

4

I’m not sure if the bug is present in newest r64,but older boards missing coupling capacitors so maybe this is the cause.

5

could be indeed. Mine is ± 3 years old, where do I see the revision? If so, what are my options?

6

hw-version is printed on the board, afair coupling capacitors weren’t added in a hw-rev, but maybe i’m not right informed

7

The hw version is silk-screened under the bpi logo, the latest is V1.2, and the PCIe capacitor problem has been fixed

1 Like
8

seems like I got the version 1.1, are there any options here?

9

This isn’t a PCIe capacitor issue. Problem exists on both my modded v1.1 board (where I fixed the issue), and my v1.2 board. In both cases I am using an AsiaRF AW7915-NP1 board in the device.

Good catch, btw. I’ve never noticed that message before.

10

how could you fix it?

11
12

The 2 shorts should be enough…