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

[Rong Zhang]

Hi Rafael,

On Tue, 2026-07-28 at 10:17 -0300, Rafael Passos wrote:
> Hi again,
> 
> On Mon Jul 6, 2026 at 4:39 PM -03, Rong Zhang wrote:
> > Hi Rafael,
> > 
> > Hmm, interesting. My speculation is that it doesn't matter which options are changed, but some changed options cause the BIOS to reinitialize something. Does resetting the BIOS settings to default help?
> 
> I was unable to trigger the same issue again. It has been working fine
> (even when running without your patch). I believe the reset with bios
> config changes fixed it for good.

Oh, that's really good news. Cheers!

> 
> 
> > Could you provide more details about your device's USB and PCI topology? Does the NIC's USB connect to one of the USB root hubs of the SoC (i.e., CPU) or the chipset?
> 
> 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'.

> 
> 
> > And I guess your device runs into the issue without any precursor? Once boot, try running the script below to capture more clues into dmesg, and wait for the issue to appear.
> > 
> >     #!/bin/sh
> > 
> >     ddcmd()
> >     {
> >         echo "$*" | sudo tee /proc/dynamic_debug/control;
> >     }
> > 
> >     ddcmd file drivers/usb/core/hub.c +p
> >     ddcmd file drivers/usb/core/driver.c +p
> >     ddcmd func handle_tx_event +p
> 
> Thanks for the script! I'm learning a bit with it!
> 
> > I would do the below experiments if I had a buggy device like that. Some extra hardware is required though.
> > 
> > Connect another NIC (w/ Bluetooth interface) to the same M.2 port after triggering the enumeration failure, and see if the enumeration failure persists.
> 
> 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 ;-)

Thanks,
Rong

> 
> [1] page 10 https://download.asrock.com/Manual/B850M%20Steel%20Legend%20WiFi.pdf
> 
> Thanks,
> Rafael Passos