Re: [PATCH bluetooth] btmtk: fix MT7927 / MT6639 firmware loading and section filtering

[Paul Menzel]

Dear Jean-François,


Thank you for your message.

Am 08.02.26 um 20:52 schrieb Jean-François Marliére:

> Bluetooth on MediaTek MT7927 (hardware variant 0x6639) is currently
> broken on Linux.
> The device is detected (USB VID:PID 0489:e13a, Foxconn/Hon Hai), but
> initialization
> fails with "Unsupported hardware variant (00006639)" or the chip hangs
> during
> firmware download.
>
> I investigated this issue by comparing Linux behavior with USB captures
> from the
> Windows driver and identified three root causes in btmtk:
>
> 1. Hardware variant 0x6639 is missing from btmtk switch/case handling
> 2. Incorrect firmware naming is used (_1_1_hdr.bin instead of
> _2_1_hdr.bin)
> 3. Critical issue: non-Bluetooth firmware sections are sent to the
> chip, which
>     causes an irreversible BT subsystem hang (requires full power cycle)
>
> The Windows driver only downloads firmware sections where
> (dlmodecrctype & 0xff) == 0x01. The MT6639 firmware contains 9
> sections, but only
> the first 5 are Bluetooth-related. Sending the remaining sections
> (WiFi/other)
> causes the failure observed on Linux.
>
> This patch:

Unfortunately, despite the subject containing the tag *PATCH*, no patch 
is included in your message – also not in the archive [1].

> - Adds support for hardware variant 0x6639
> - Uses the correct firmware naming format for MT6639
> - Filters firmware sections to only download Bluetooth sections
>    (dlmodecrctype & 0xff == 0x01), matching Windows driver behavior
>
> Tested on:
>
> - Debian 13 (Trixie)
> - Kernel 6.12.63
> - ASUS ProArt X870E-CREATOR-WIFI motherboard
> - MediaTek MT7927 / MT6639 Bluetooth
>
> A full technical analysis, reproduction steps, and testing details are
> available here:
> https://gitlab.com/jfmarliere/linux-driver-mediatek-mt7927-bluetooth

Great work!

> Please let me know if you would prefer this split into multiple patches
> or if additional testing/logs are required.
If a patch can be split, I would split it with a dedicated commit 
message, and Signed-off-by line, and Link: tags – like the newly created 
bug report [2]. Please note, that patches for the Bluetooth subsystem 
need to be have the prefix `Bluetooth: `. `git log drivers/bluetooth` 
should give you some examples – also what logs to include.

I am looking forward to your patch submissions.


Kind regards,

Paul


PS: Please note, that

Marliére Jean-François <freelance@xxxxxxxxxxx>

looks strange, and a comma is missing or the given name should come first.


[1]: 
https://lore.kernel.org/all/496b0f8505eb6ffb19fdbee6f963c62aa6790fba.camel@xxxxxxxxxxx/
[2]: https://bugzilla.kernel.org/show_bug.cgi?id=221096