Re: ODROID-C1/-C2 USB Detection only triggered by some devices dwc2

From: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
To: Minas Harutyunyan <Minas.Harutyunyan@synopsys.com>
Cc: Alan Stern <stern@rowland.harvard.edu>,
	Matt Corallo <oc2udbzfd@mattcorallo.com>,
	 "linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>,
	 "linux-amlogic@lists.infradead.org"
	<linux-amlogic@lists.infradead.org>,
	 "linux.amoon@gmail.com" <linux.amoon@gmail.com>,
	Artur Petrosyan <Arthur.Petrosyan@synopsys.com>
Subject: Re: ODROID-C1/-C2 USB Detection only triggered by some devices dwc2
Date: Mon, 10 Jan 2022 23:05:05 +0100	[thread overview]
Message-ID: <CAFBinCAMJXtK4VOknGmfPB0GwHnJNtQ8gSMwQR-8a-gJP6jL6g@mail.gmail.com> (raw)
In-Reply-To: <CAFBinCAvFbLXoobcTWiOoUrRSFnNzhOdn-=dkxvJOMkeOC+EAg@mail.gmail.com>

Hi Minas,

On Sun, Dec 12, 2021 at 5:08 PM Martin Blumenstingl
<martin.blumenstingl@googlemail.com> wrote:
[...]
> On Tue, Aug 3, 2021 at 11:32 PM Alan Stern <stern@rowland.harvard.edu> wrote:
> >
> > Minas, you should look at analysis of the usbmon information below.
> Minas, it would be great if you could take the time to go through
> Alan's findings.
> Since it's been a while I am trying to summarize the current state of
> the findings here.
Since I sent my last email you were probably on vacation. I hope you
had a good time!

> In [0] Alan mentioned:
> > Minas, some of the things noted below may require your attention. In
> > particular, the usbmon traces don't show the root hub doing what it should,
> > which leads me to wonder whether the Genesys Logic hub attached to port 1
> > really is getting suspended and resumed properly.
>
> Then in [1] Alan goes through the usbmon traces from my Meson8b
> Odroid-C1+ and comes to the following conclusion:
> > [...] the trace shows that the GL hub was never fully suspended!
> >
> > So the question is: Why doesn't the port status on the DWC2 root hub
> > show the suspend feature set, and why doesn't the root hub port get
> > suspended?  This looks like a bug in the dwc2 driver. [...]
>
> Linux 5.16-rc4 is still affected by this issue, meaning that it hasn't
> been fixed in the meantime.
>
> I am happy about any feedback which can help resolve this issue. That
> means: even if you have an idea (like: flipping bit X in register Y
> could help) which you are unable to test yourself then please let me
> know - I can take care of the testing part (and share debug
> logs/usbmon traces if needed).
Could you please take out some time to go through Alan's findings and
let me know if/what you need from my end so we can resolve this issue?

Thank you!
Best regards,
Martin

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