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The Void source packages collection
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Enable CONFIG_BT_HCIBTUSB_MTK in package linux5.x #34554

Closed rubin55 closed 2 years ago

rubin55 commented 2 years ago

System

Expected behavior

cat /boot/config-5.15.7_1 | grep CONFIG_BT_HCIBTUSB_MTK
CONFIG_BT_HCIBTUSB_MTK=m

Actual behavior

cat /boot/config-5.15.7_1 | grep CONFIG_BT_HCIBTUSB_MTK
# CONFIG_BT_HCIBTUSB_MTK is not set

Steps to reproduce the behavior

See above. This is simply a feature-request to enable CONFIG_BT_HCIBTUSB_MTK so that MediaTek based HCI bluetooth USB controllers start working (encountered this particular controller on my new AMD Ryzen 5850U based ThinkPad P14s).

rubin55 commented 2 years ago

@leahneukirchen Is it possible to enable this also for the older kernels? Specifically I'm thinking about whichever version would have introduced the CONFIG_BT_HCIBTUSB_MTK flag, but at least 5.12, 5.13 and 5.14?

leahneukirchen commented 2 years ago

I wont bump EOL kernels, sorry.

ericonr commented 2 years ago

linux5.12 has already been removed from source repos, and linux5.13 and 5.14 will soon be removed.

rubin55 commented 2 years ago

Ok fair enough. For posterity, I ran into an issue when both Bluetooth and Wi-Fi were enabled and thought it was a recent regression in the Linux kernel, hence the wish to have it available in older kernel versions.

Turns out this issue exists on older kernel versions equally. I wrote about the issue here: https://www.reddit.com/r/thinkpad/comments/rkvggg/thinkpad_p14s_gen2_amd_linux_515_mediatek_7961/

TL;DR; if you come here and think you have an issue with mt7921e and/or with btusb, check your wireless band with iwconfig wlan0. If its in the ~2.4Ghz range, you will find that it is very likely conflicting with your bluetooth stack which is also operating within the same range. Quick workaround: make sure you have a Wi-Fi router that can do ~5Ghz and connect your Wi-Fi on the ~5Ghz band, which avoids conflict with your bluetooth stack.

Other drivers (i.e., iwl2200) have a bt_coex option that seems to avoid this issue. mt7921e does not have this option (yet?). I emailed Sean Wang, who is one of the developers at MediaTek who works on mt7921e to share my experiences.