Re: [PATCH v2 1/1] Bluetooth: hci_ll: Enable BROKEN_ENHANCED_SETUP_SYNC_CONN for WL183x

[Stefano Radaelli]

Hi Paul,

On Thu, Apr 02, 2026 at 10:51:01PM +0200, Paul Menzel wrote:
> 
> Do you have a reproducer?
> 

Yes,
the issue can be reproduced on our Variscite platforms using TI WL183x
modules (e.g. VAR-SOM-MX6). When establishing an SCO connection using
the HCI Enhanced Setup Synchronous Connection command.

Forcing the legacy HCI Setup Synchronous Connection (0x0028) instead
restores correct SCO operation.

> Have you contacted TI about this?
> 

No, we have not contacted TI.

WL183x devices are quite old (released more than 10 years ago), and the
latest available firmware is also quite dated and predates the
introduction of the Enhanced Setup Synchronous Connection handling in
the Linux kernel.

Given this, these devices cannot realistically work correctly with this
command unless a new firmware update is provided by TI, which seems
unlikely at this point.

> 
> Do you have an example device, that uses one of these? 

Yes, for example the VAR-SOM-MX6, which integrates WL183x modules.
The issue has been consistently observed across our platforms using
WL1831, WL1835 and WL1837 modules.

>Also, do you know of
> TI device, where the HCI Enhanced Setup Synchronous Connection command
> works?
> 

At the moment I do not have access to other TI Bluetooth families using
this driver to verify whether the enhanced command works correctly on
newer devices.

For this reason, the patch limits the quirk only to the WL183x family,
based on the compatible string, and does not affect other TI devices
handled by hci_ll. Additional compatibles can be added in the future if
similar behaviour is observed on other controllers.

Thanks for your review!

Best Regards,
Stefano