Re: [PATCH v6 6/9] usb: misc: qcom_eud: add role-based EUD control
From: Konrad Dybcio
Date: Mon Aug 24 2026 - 09:46:58 EST
On 8/11/26 11:36 PM, Elson Serrao wrote:
> EUD functions by presenting itself as a USB device to the host PC and is
> therefore only applicable when the port operates in device role. Keeping
> EUD enabled in other roles provides no benefit and unnecessarily keeps
> the associated PHY resources enabled. Furthermore, enabling EUD in host
> role can cause the USB controller to misbehave because the EUD hub
> supports only a single upstream-facing port.
>
> Address this by treating EUD as usable only in device role. The
> role-switch callback enables or disables EUD as the port enters or
> leaves device role. A sysfs enable request made outside device role is
> recorded and honored when the port subsequently switches to device role.
>
> Reviewed-by: Peter Chen <peter.chen@xxxxxxxxxx>
> Signed-off-by: Elson Serrao <elson.serrao@xxxxxxxxxxxxxxxx>
> ---
Reviewed-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxxxxxxxx>
Konrad