Re: [PATCH v1] arm64: dts: qcom: hamoa-iot-evk: support Bluetooth over both USB and UART

[Dmitry Baryshkov]

On Fri, Mar 13, 2026 at 02:37:39PM +0800, Shuai Zhang wrote:
> Hi Konrad
> 
> On 3/11/2026 9:07 PM, Konrad Dybcio wrote:
> > On 3/11/26 10:09 AM, Shuai Zhang wrote:
> > > When Bluetooth supports both USB and UART, the BT UART driver is
> > > always loaded, while USB is hot-pluggable. As a result, when Bluetooth
> > > is used over USB, the UART driver still be probed and drive BT_EN low,
> > > which causes the Bluetooth device on USB to be disconnected.
> > Is bluetooth connected over UART *and* USB simultaneously?
> BT uses either UART or USB, never both at the same time.
> 
> On platforms supporting both, the UART driver is always probed, while USB is
> hot‑pluggable.
> 
> As a result, when BT runs over USB, the UART driver still probes and pulls
> BT_EN low,
> 
> unintentionally powering off the USB BT device.

Could you please confirm if [1] would solve the problem?


[1] https://lore.kernel.org/r/20260224-pci-m2-e-v5-9-dd9b9501d33c@xxxxxxxxxxxxxxxx

> 
> > 
> > > Configure BT_EN as a GPIO hog so that it is controlled by the platform
> > What's "the platform"?
> 
> hamoa-evk
> 
> 

-- 
With best wishes
Dmitry