Date: Wed, 21 Feb 2018 12:11:19 -0800 From: bob prohaska <fbsd@www.zefox.net> To: "Rodney W. Grimes" <freebsd-rwg@pdx.rh.CN85.dnsmgr.net> Cc: freebsd-arm@freebsd.org, bob prohaska <fbsd@www.zefox.net> Subject: Re: Scrambled console on RPi3 Message-ID: <20180221201118.GB696@www.zefox.net> In-Reply-To: <201802211811.w1LIBUAe087135@pdx.rh.CN85.dnsmgr.net> References: <20180221170923.GA19462@www.zefox.net> <201802211811.w1LIBUAe087135@pdx.rh.CN85.dnsmgr.net>
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On Wed, Feb 21, 2018 at 10:11:30AM -0800, Rodney W. Grimes wrote: > > A few minutes ago I unplugged and replugged a PL2303 serial adapter in an > > RPi3 running r329495. The serial console announced the disconnection with > > ugen0.4: <vendor 0x067b product 0x2303> at usbus0 (disconnected) > > uplcom0: at uhub1, port 2, addr 4 (disconnected) > > uplcom0: detached > > > > followed by a torrent of unprintable garbage. Then it calmly announced > > > > <vendor 0x067b product 0x2303> at usbus0 > > uplcom0 on uhub1 > > uplcom0: <vendor 0x067b product 0x2303, class 0/0, rev 1.10/4.00, addr 4> on usbus0 > > > > The displaying host is a Pi3 running the latest Raspbian. It's not clear > > how much, if any, of the oddity is an artifact of the display. Experience > > to date suggests none. > > > > Far as I can tell the pl2303 and the host RPi3 are working normally. I've > > never done this experiment before on a Pi3, but have done it many times on > > a Pi2 and nothing of the sort has happened. > > > > Hope this is of interest to someone... > > Do you have which 4 wires connected? > Gnd - should be connected > TX - should be connected > RX - should be connected > Vcc - Do not connect this wire, doing so can lead to odd behavior > unless you happen to be powering the device this way, and > in your case, the RPi3 has a higher load current than USB > can normally supply. Yes, the wiring was correct, working before & after and untouched during the incident. For clarity, the USB-side connect/disconnect and scrambled console were on the Pi3. The "client" serial connection was to a Pi2 console which seemed, and after several hours remains, unperturbed. The console of the Pi3 was being viewed on a Raspbian Pi3 wirelessly connected by ssh to a Pi2, which used a second pl2303 to monitor the Pi3 console in a cu session. The latter two hosts are running -current, both are prone to dropping ssh connections when loaded and the pl2303 is prone to lockups as noted elsewhere on this list. The unplug/replug cycle was done to unstick the pl2303 in the Pi3. For the moment I'm tempted to think it's a USB problem, which could affect both ethernet and usb serial adapters. Thanks for reading! bob prohaska
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