Bug 204585

Summary: Bluetooth Mouse Polling Rate Regressed to 20hz
Product: Drivers Reporter: Ivan Svalov (worryag)
Component: BluetoothAssignee: linux-bluetooth (linux-bluetooth)
Severity: normal CC: leif.liddy, mybigspam, pavel, saroumane, worryag
Priority: P1 Keywords: trivial
Hardware: All   
OS: Linux   
URL: https://bbs.archlinux.org/viewtopic.php?id=248133
Kernel Version: Linux arch 5.2.8-arch1-1-ARCH Subsystem:
Regression: No Bisected commit-id:
Attachments: pairing issue capture

Description Ivan Svalov 2019-08-14 18:22:59 UTC
The problem arose with Microsoft BluetoothMouse3600. When you turn on the mouse behaves sluggishly. The evhz utility shows a polling rate of 20Hz. The problem is solved by changing the max and min values of the connection.

/usr/bin/hcitool con | grep " handle " | awk '{print $5}' | xargs -I {} /usr/bin/hcitool lecup --handle {}  --min 6 --max 7 --latency 0

Maybe you should change the default value of conn_min_interval and conn_max_interval.
Comment 1 Leif Liddy 2019-09-08 11:56:02 UTC
I'm seeing this exact same issue with an orochi (2015) mouse on my laptop running kernel 5.2.11
What'd odd is that this issue isn't present when using this mouse on my other laptop running the same distro + kernel (but different bluetooth chipset).

Not sure when this issue started exactly, but it was either kernel 5.1.x or 5.2.x.  

The stated hcitool command solves the issue for me. Since hcitool is deprecated, what is the 'proper' method we're meant to use to implement this change?

I'm not able to change the polling intervals via debugfs as conn_min_interval and conn_max_interval don't exist

# find /sys/kernel/debug/bluetooth/hci0 -type f 
Comment 2 Leif Liddy 2019-09-08 13:27:05 UTC
Looks like that patch is getting reverted:
Comment 4 Pavel 2019-09-12 12:47:19 UTC
Created attachment 284937 [details]
pairing issue capture

I am experiencing pairing issues after reversal
Comment 5 Pavel 2019-09-12 12:53:06 UTC
My device is rapoo 550 made on MXCHIP btle chipset
Comment 6 Pavel 2019-09-14 13:17:32 UTC
Guys on https://bbs.archlinux.org/viewtopic.php?id=248133 clearly singled out the issue as a matter of changes in default settings and conn_min_interval
Comment 7 Ivan Svalov 2019-09-17 13:22:27 UTC
Applying a patch https://www.spinics.net/lists/linux-bluetooth/msg81235.html solves a problem with my mouse. Kernel 5.2.15
Comment 8 Leif Liddy 2019-09-24 11:53:37 UTC
This is only a temporary solution (until commit c49a8682fc5d gets reverted). If you read the very next message in that email chain:

The subsystem maintainer, Marcel Holtmann replies to the proposed change:
"I decided to revert c49a8682fc5d and we need an overall better solution for handling connection parameters"
Comment 9 Sar 2019-11-06 15:53:58 UTC
The problem is still here on kernel 5.3.0-19-generic

I discovered it with my Logitech M535 bluetooth mouse.

The workaround (overriding /sys/kernel/debug/bluetooth/hci0/conn_min_interval and conn_max_interval) works.