Re: [PATCH 2/2] usb: core: Add tracepoints for device allocation and state changes

[Kuen-Han Tsai]

On Tue, Oct 14, 2025 at 3:57 PM Greg Kroah-Hartman
<gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
>
> On Mon, Oct 13, 2025 at 10:01:23AM +0800, Kuen-Han Tsai wrote:
> > Introduce new tracepoints to the USB core to improve debuggability of
> > USB device lifecycle events.
> >
> > The following tracepoints are added:
> >
> > - usb_alloc_dev: Triggered when a new USB device structure is allocated,
> > providing insights into early device setup.
> > - usb_set_device_state: Triggered when the USB device state changes,
> > allowing observation of the device's state transitions.
> >
> > These tracepoints capture detailed information about the USB device,
> > including its name, speed, state, bus current value, and authorized
> > flag. This will aid developers in diagnosing issues related to device
> > enumeration within the USB subsystem.
> >
> > Examples:
> >  usb_alloc_dev: usb 1-1 speed 0 state 1 0mA [authorized]
>
> If you are going to change the state to be a string, can you also change
> the speed to be a string as well?  That will help out with people
> wondering what is going on with the speed of the device a lot.
>

Will do. I will update both the speed and state to be strings.

Regards,
Kuen-Han