Hi, Thomas,

On Wed, Dec 8, 2021 at 8:58 AM Thomas Bogendoerfer
[off-list ref] wrote:

Hi,

I'm getting lots of

[    2.940587] pci 0000:00:04.1: EHCI: unrecognized capability ff
[    2.946478] pci 0000:00:04.1: EHCI: unrecognized capability ff
[    2.952374] pci 0000:00:04.1: EHCI: unrecognized capability ff
[    2.958270] pci 0000:00:04.1: EHCI: unrecognized capability ff
[    2.964166] pci 0000:00:04.1: EHCI: unrecognized capability ff
[    2.970062] pci 0000:00:04.1: EHCI: unrecognized capability ff

while booting on a Loongson-3A R4 (Loongson-3A4000) @ 1800MHz system.
What I'm missing ?

This is a hardware issue of LS7A bridge.

I'm also seeing

[    1.222546] pci_bus 0000:00: 2-byte config write to 0000:00:00.0 offset 0x4 m
ay corrupt adjacent RW1C bits
[    1.232314] pci_bus 0000:00: 2-byte config write to 0000:00:00.0 offset 0x4 m
ay corrupt adjacent RW1C bits

which look suspicous...

This can be avoid and I have send a patch, but hasn't accepted yet.
https://lore.kernel.org/linux-pci/20211011074604.854340-2-chenhuacai@loongson.cn/T/#u (local)

Huacai

Thomas.

--
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea.                                                [ RFC1925, 2.3 ]