qca/hci issues with Bluetooth on Dell XPS 13/AX500 (9310)

[Jens Gecius]

Am 11.05.21 um 15:02 schrieb Jens Gecius:
> Dear all,
>
> there was an earlier (March 30 "issues with QCA6390 on Dell XPS 13") 
> report of the same/similar problem (just realized today).
>
> As that reporter, I have a Dell XPS 13 dev edition/Ubuntu (working). 
> My 9310 has the AX500 Killer Wifi. Wifi is working fine, but Bluetooth 
> always gives me a crash (I blacklisted BT required modules to later 
> trigger the oops myself or run without). The crash renders the 
> suspend/resume capabilities inoperable, the hci_uart module is not 
> removeable.
>
> I tried to get differences of the Dell supplied Ubuntu-OEM 5.6 kernel 
> to current mainline, but my grey matter is unable to digest that 
> information and supply helpful hints.
> /lib/firmware-files were the same on Ubuntu and Fedora (it recently 
> got updated on my Fedora 34 - crash unchanged).
>
> Full dmesg output of module loading attached.
>
> Intentionally, I did a suspend-resume cycle first for your kind 
> information and then loaded the BT modules. The crash also occurs if I 
> load the hci_uart directly after system startup.
>
> That is unchanged since receiving the notebook in April, even with 
> earlier firmware version. I am on the latest Fedora kernel, now 
> 5.11.18-300.fc34.x86_64. BIOS is latest 2.2.0.
>
> The trace says, that qca_read_soc_version is causing the crash during 
> qca_uart_setup in btqca. Is that correct?
>

Just to report back, that bluetooth works with 5.12.11 (.10 didn't). As 
far as I can see, a change to net/bluetooth/hci_core.c was made. Not 
sure, if this is the relevant change.



> And - maybe I'm on the wrong list here (BT / ath11k) anyway, please 
> let me know if so. :-)
>
> If I can support, please let me know. Thank you very much.
>
> Best
>  Jens
>