On 01/01/2022 11:03, Chris Clayton wrote: > > > On 31/12/2021 19:53, Luiz Augusto von Dentz wrote: >> Hi Chris, >> >> On Fri, Dec 31, 2021 at 2:35 AM Chris Clayton wrote: >>> >>> On 30/12/2021 09:21, Chris Clayton wrote: >>>> Hi, >>>> >>>> I pulled the latest changes into my clone of Linus' tree and built and installed the kernel. (git describe gives >>>> v5.16-rc7-9-ge7c124bd0463). I'm seeing errors reported by the bluetooth subsystem that i don't see in 5.15.12 or 5.10.89 >>>> >>>> The problem seems to occur twice during system startup and on each occasion I see a batch of identical error messages: >>>> >>>> [ 3.980822] Bluetooth: hci0: Failed to read codec capabilities (-56) >>>> [ 3.982812] Bluetooth: hci0: Failed to read codec capabilities (-56) >>>> [ 3.984812] Bluetooth: hci0: Failed to read codec capabilities (-56) >>>> [ 3.986608] Bluetooth: hci0: Failed to read codec capabilities (-56) >>>> [ 3.987621] Bluetooth: hci0: Failed to read codec capabilities (-56) >>>> [ 3.988606] Bluetooth: hci0: Failed to read codec capabilities (-56) >>>> [ 3.989650] Bluetooth: hci0: Failed to read codec capabilities (-56) >>>> >>> >>> Sorry, I should have said that despite the above errors, my bluetooth devices still work fine. >> >> Would be great to have the HCI trace (btmon). >> > > How would I go about capturing that, please? This all happens during boot, so I don't have access to the system to set > up a trace. > I thought about this a bit more and realised that one batch of the errors messages occurs when the bluetooth service is being started in userspace. Si I stopped that service, started btmon and restarted the service. The trace is attached. The error messages I am seeing seem to coincide with the "Status: Unknown HCI Command (0x01)" messages that are in the trace. The first instance of that is at line 951 of the trace. > >> @Kiran K Is this to be expected? >> >>> >>>> A full dmesg log is attached. I've also attached Two files containing the output from "lsusb -v" run on 5.10.89 and >>>> 5.16-rc7. >>>> >>>> Please let me know if I can provide any other diagnostic information or test any patches. You'll need to cc me on >>>> replies because I'm not subscribed to LKML or linux-bluetooth. >>>> >>>> Thanks >> >> >>