Re: 5.16.0-rc7+ Bluetooth error

[Chris Clayton]

On 03/01/2022 09:55, K, Kiran wrote:
> Hi Luiz, Chris,
> 
>> -----Original Message-----
>> From: Luiz Augusto von Dentz <luiz.dentz@xxxxxxxxx>
>> Sent: Saturday, January 1, 2022 1:23 AM
>> To: Chris Clayton <chris2553@xxxxxxxxxxxxxx>
>> Cc: LKML <linux-kernel@xxxxxxxxxxxxxxx>; linux-bluetooth@xxxxxxxxxxxxxxx;
>> K, Kiran <kiran.k@xxxxxxxxx>
>> Subject: Re: 5.16.0-rc7+ Bluetooth error
>>
>> Hi Chris,
>>
>> On Fri, Dec 31, 2021 at 2:35 AM Chris Clayton <chris2553@xxxxxxxxxxxxxx>
>> 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).
>>
>> @Kiran K Is this to be expected?
> 
> May be the BT controller here is not supporting HCI_READ_CODEC_CAPABILITIES command.
> 
> This has been fixed - https://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth-next.git/commit/?id=107fe0482b549a0e43a971e5fd104719c6e495ef
> 

I've applied the patch to 5.16.0-rc8 and the error messages are no longer produced. My bluetooth devices are stiil working.

Tested-By: Chris Clayton <chris2553@xxxxxxxxxxxxxx>

> A check has been added to read codec capabilities only if supported.
> 
> Thanks,
> Kiran
>