Bluetooth connection drops after idle time

Bluetooth connection drops after idle time

[Dr Nukular]

Bluetooth connection drops if the device, such as mouse or keyboard, is inactive for some time. Once the device is used again the bluetooth connection comes back on. This would not be an issue, if it wasn't for the time that it takes until the connection is re-established again. It is not responsive enough and interferes with the workflow, if you have to wait several seconds until you can use your device again, especially since you naturally expect an immediate response.

If this is not a bug, then please enable a setting to disable that "feature" or improve the time by reducing it to a minimum to reconnect the device.

Re: Bluetooth connection drops after idle time

[Joseph Hwang]

Hi Dr Nukular:

  As far as I know, it is the peripheral device that enters power
saving mode and disconnects.

On Sat, Apr 7, 2018 at 2:32 PM, Dr Nukular <dr.nukular@outlook.at> wrote:
>
> Bluetooth connection drops if the device, such as mouse or keyboard, is i=
nactive for some time. Once the device is used again the bluetooth connecti=
on comes back on. This would not be an issue, if it wasn't for the time tha=
t it takes until the connection is re-established again. It is not responsi=
ve enough and interferes with the workflow, if you have to wait several sec=
onds until you can use your device again, especially since you naturally ex=
pect an immediate response.
>
> If this is not a bug, then please enable a setting to disable that "featu=
re" or improve the time by reducing it to a minimum to reconnect the device=
.--
> To unsubscribe from this list: send the line "unsubscribe linux-bluetooth=
" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html



--=20

Joseph Shyh-In Hwang
Email: josephsih@google.com

Re: Bluetooth connection drops after idle time

[Joseph Hwang]

Hi Dr Nukular:

  You could run "btmon -w btsnoop.log" to capture the HCI logs, have
your devices connected, let them idle for a while, and observe which
side terminates the connection.

  Also please make sure if you use the same peripheral devices when
you compare the re-connection latency before and after you upgrade
kernel/system. Bluetooth classic mouse/keyboard work differently from
BLE mouse/keyboard. When a classic bluetooth device disconnects, its
input node will be removed from kernel. Next time when reconnecting,
it needs to create its node again in kernel. On the other hand, when a
BLE device disconnects, its input node remains. Hence, a BLE device is
supposed to be a bit faster to reconnect.

Joseph


On Tue, Apr 10, 2018 at 2:06 AM, Dr Nukular <dr.nukular@outlook.at> wrote:
> Hi Joseph,
>
>
> Thanks for the reply. Not sure, but that might be the case, however this
> issue started after a kernel / system update. Does that mean that before the
> update the system was ignoring the power saving mode of that device? In that
> case what changed exactly?
>
>
> Fedora 27. kernel 4.15.14. gnome-shell 3.26.2 gnome-bluetooth 3.26.1.
>
> ________________________________
> Von: Joseph Hwang <josephsih@google.com>
> Gesendet: Montag, 9. April 2018 04:51:14
> An: Dr Nukular
> Cc: linux-bluetooth@vger.kernel.org
> Betreff: Re: Bluetooth connection drops after idle time
>
> Hi Dr Nukular:
>
>   As far as I know, it is the peripheral device that enters power
> saving mode and disconnects.
>
> On Sat, Apr 7, 2018 at 2:32 PM, Dr Nukular <dr.nukular@outlook.at> wrote:
>>
>> Bluetooth connection drops if the device, such as mouse or keyboard, is
>> inactive for some time. Once the device is used again the bluetooth
>> connection comes back on. This would not be an issue, if it wasn't for the
>> time that it takes until the connection is re-established again. It is not
>> responsive enough and interferes with the workflow, if you have to wait
>> several seconds until you can use your device again, especially since you
>> naturally expect an immediate response.
>>
>> If this is not a bug, then please enable a setting to disable that
>> "feature" or improve the time by reducing it to a minimum to reconnect the
>> device.--
>> To unsubscribe from this list: send the line "unsubscribe linux-bluetooth"
>> in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>
>
>
> --
>
> Joseph Shyh-In Hwang
> Email: josephsih@google.com



-- 

Joseph Shyh-In Hwang
Email: josephsih@google.com