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

From: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
To: Minas Harutyunyan <hminas@synopsys.com>
Cc: Alan Stern <stern@rowland.harvard.edu>,
	Matt Corallo <oc2udbzfd@mattcorallo.com>,
	 linux-usb@vger.kernel.org, linux-amlogic@lists.infradead.org,
	 linux.amoon@gmail.com
Subject: Re: ODROID-C1/-C2 USB Detection only triggered by some devices
Date: Sat, 10 Jul 2021 19:07:54 +0200	[thread overview]
Message-ID: <CAFBinCA083iP4T2b1+MoDGZFKMO8eyy-WceRBA-QibatqboO1A@mail.gmail.com> (raw)
In-Reply-To: <CAFBinCDc6RUypJpujmYdkjo6j-xsg0HkZEZGxTCsTW4tZ-bJPA@mail.gmail.com>

Hi Minas,

On Thu, Jul 1, 2021 at 1:09 AM Martin Blumenstingl
<martin.blumenstingl@googlemail.com> wrote:
>
> Hi Minas,
>
> On Tue, Jun 29, 2021 at 6:30 PM Martin Blumenstingl
> <martin.blumenstingl@googlemail.com> wrote:
> >
> > Hi Alan,
> >
> > On Tue, Jun 29, 2021 at 6:18 PM Alan Stern <stern@rowland.harvard.edu> wrote:
> > [...]
> > > > >         usbcore.autosuspend=-1
> > > > wow, this helps indeed
> > > > my steps are:
> > > > - power off my Odroid-C1+
> > > > - unplug all USB devices
> > > > - boot with usbcore.autosuspend=-1 in the kernel cmdline
> > > > - plugin my Corsair Voyager USB 3.0 flash drive (which was only
> > > > detected before if an additional USB 2.0 flash drive was plugged in
> > > > during boot)
> > > > -> without any lsusb magic the device was immediately recognized
> > >
> > > That does show pretty convincingly that runtime suspend is causing the
> > > problem.  But I still have no idea why the problem affects some devices
> > > and not others.  It's a mystery.
> > Maybe because there's two related problems (I am guessing here):
> > The first issue is that USB hotplug is not working at all on my
> > Odroid-C1+ (which means: dwc2 + GL852G USB hub).
> > The second issue is that the workaround we had before (running lsusb
> > -vv to make "hot plugged" devices show up) is not working for some USB
> > devices.
> >
> > It seems that using a different workaround (usbcore.autosuspend=-1)
> > makes *all* USB devices show up - even without any "lsusb -vv" call.
> > So I think we should focus on the first issue as it may also fix the
> > other problem as well.
> above paragraph sums up the issues which Matt and I are seeing (on
> Odroid-C1+ and Odroid-C2) in case you didn't follow the full email
> thread
It's been a week since I sent my last mail
In case you are taking some days off: enjoy that time!
Please let us know if you have any questions about this as we're
looking forward to some hints on how to debug (and of course fix!)
this.

Best regards,
Martin

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