Re: [PATCH v2] Bluetooth: Properly disable remote wakeup for MT7922/MT7925 on Ryzen platform

[Rafael Passos]

Hi Rong,

On Tue Jul 28, 2026 at 11:00 AM -03, Rong Zhang wrote:
>> I believe its a hub connected to the chipset.
>> 
>> /:  Bus 001.Port 001: Dev 001, Class=root_hub, Driver=xhci_hcd/12p, 480M
>>     | ...
>>     |__ Port 008: Dev 004, If 0, Class=Wireless, Driver=btusb, 480M
>> 
>> In the block diagram on the manual [1], Key "E" Wifi is tied
>> to the AMD PROM21 CHipset.
>
> Yes, and no.
>
> The block diagram indicates that the NIC card's PCIe interface (note the
> "x1") is connected to the chipset, without any mention of its USB
> interface.
>
> Based on the bus number (001), it's more likely a root hub of the SoC
> instead of the chipset.
>
> You can check the root hub's PCI path with
>
>    realpath /sys/bus/usb/devices/usb1
>
> Then you can cross-check with the PCI topology, i.e., `lspci -tnnnvvv'.

Interesting!

lspci -tnnnvvv
-[0000:00]-+-00.0  Advanced Micro Devices, Inc. [AMD] Raphael/Granite Ridge Root Complex [1022:14d8]
           +-00.2  Advanced Micro Devices, Inc. [AMD] Raphael/Granite Ridge IOMMU [1022:14d9]
           +-01.0  Advanced Micro Devices, Inc. [AMD] Raphael/Granite Ridge Dummy Host Bridge [1022:14da]
           +-01.1-[01-03]----00.0-[02-03]----00.0-[03]--+-00.0  Advanced Micro Devices, Inc. [AMD/ATI] Navi 21 [Radeon RX 6800/6800 XT / 6900 XT] [1002:73bf]
           |                                            \-00.1  Advanced Micro Devices, Inc. [AMD/ATI] Navi 21/23 HDMI/DP Audio Controller [1002:ab28]
           +-02.0  Advanced Micro Devices, Inc. [AMD] Raphael/Granite Ridge Dummy Host Bridge [1022:14da]
           +-02.1-[04-0e]----00.0-[05-0e]--+-00.0-[06]--
           |                               +-02.0-[07]----00.0  MEDIATEK Corp. MT7925 (RZ717) Wi-Fi 7 160MHz [14c3:0717]
           |                               +-03.0-[08]----00.0  Realtek Semiconductor Co., Ltd. RTL8125 2.5GbE Controller [10ec:8125]
           ...


realpath /sys/bus/usb/devices/usb1
/sys/devices/pci0000:00/0000:00:02.1/0000:04:00.0/0000:05:0c.0/0000:0d:00.0/usb1
                ------               --------------------
                /                    |
        This matches the             \--and this matches the chain before
        root complex                    the MT7925.

Am I on the right path ?

>> It is integrated (soldered) to my motherboard.
>
> Huh? How can an M.2 "Key E WiFi" expansion card being soldered to a
> "vertical M.2 socket"?
>
> AFAIK, once the metal shield(s) are unscrewed, it should be replaceable,
> see
> https://www.techpowerup.com/review/asrock-b850-steel-legend-wi-fi/4.html
>
> But it doesn't matter anyway since the issue has gone ;-)

Oh ! Its vertical ! You nailed it!
I assumed it was soldered because there was no space there for a
horizontal layout (and I didnt try unscrewing it). Neat!

Thanks,
Rafael Passos