Re: [PATCH] usb: dwc3: gadget: Inform system of suspended state

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On Wed, Jun 05, 2024, Mike Looijmans wrote:
> On 05-06-2024 01:06, Thinh Nguyen wrote:
> > Hi,
> > 
> > On Tue, Jun 04, 2024, Mike Looijmans wrote:
> > > On 04-06-2024 03:03, Thinh Nguyen wrote:
> > > > Hi,
> > > > 
> > > > On Mon, Jun 03, 2024, Mike Looijmans wrote:
> > > > > When disconnecting the USB cable on an LS1028 device, nothing happens
> > > > > in userspace, which keeps thinking everything is still up and running.
> > > > > Turns out that the DWC3 controller only sends DWC3_DEVICE_EVENT_SUSPEND
> > > > > in that case, and not a DWC3_DEVICE_EVENT_DISCONNECT as one would
> > > > > expect. As a result, sysfs attribute "state" remains "configured"
> > > > > until something resets it.
> > > > > 
> > > > > Forward the "suspended" state to sysfs, so that the "state" at least
> > > > > changes into "suspended" when one removes the cable, and hence also
> > > > > matches the gadget's state when really suspended.
> > > > On disconnection, did you see disconnect interrupt? If so, it should
> > > > transition to USB_STATE_NOATTACHED. This change doesn't seem to directly
> > > > address your issue. Can you provide the driver tracepoints?
> > > The device doesn't issue a disconnect event, I didn't have tracing enabled
> > > in the kernel but added some dev_info() calls to determine what was going
> > > on. Added this to dwc3_process_event_entry():
> > > 
> > > dev_info(dwc->dev, "event: 0x%x type=0x%x", event->raw, event->type.type);
> > > 
> > > When disconnecting the cable from the host, I see this:
> > > 
> > > [   50.841411] dwc3 3110000.usb: event: 0x6084 type=0x42
> > > [   50.841457] dwc3 3110000.usb: event: 0x4086 type=0x43
> > > [   50.841494] dwc3 3110000.usb: event: 0x6084 type=0x42
> > > [   50.841534] dwc3 3110000.usb: event: 0x4086 type=0x43
> > > [   50.841571] dwc3 3110000.usb: event: 0x4086 type=0x43
> > > [   52.650990] dwc3 3110000.usb: event: 0x30601 type=0x0
> > > 
> > > The "0x4086" and "0x6084" messages are endpoint events that occur all the
> > > time while connected. The last event is the "suspend" one. After that, total
> > > silence.
> > > 
> > > If you need traces, please point me to a description on how to obtain them.
> > > 
> > > 
> > Let me know if you run into issues following this instructions to
> > capture the tracepoints:
> > https://urldefense.com/v3/__https://docs.kernel.org/driver-api/usb/dwc3.html*required-information__;Iw!!A4F2R9G_pg!bahfjil5HEUq-fOHAwDfusutLJCLognfyLHTFLiSlVuZotpr99XBGg7nB0zRRnNF_M1pqEKcVa4KxNJwh3_F2dZWwVKTkUY$
> I've attached the traces as a tarball. Hope it survives.

Got them. Thanks.

> 
> At the start, the USB is up and running (and doing ethernet+mass storage). I
> saved the trace after pulling the USB cable.
> 


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