From owner-freebsd-arm@freebsd.org  Mon Jan  1 18:10:55 2018
Return-Path: <owner-freebsd-arm@freebsd.org>
Delivered-To: freebsd-arm@mailman.ysv.freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org
 [IPv6:2001:1900:2254:206a::19:1])
 by mailman.ysv.freebsd.org (Postfix) with ESMTP id 94A8DEB58E5
 for <freebsd-arm@mailman.ysv.freebsd.org>;
 Mon,  1 Jan 2018 18:10:55 +0000 (UTC)
 (envelope-from fbsd@www.zefox.net)
Received: from www.zefox.net (www.zefox.net [69.239.235.194])
 (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
 (Client CN "www.zefox.org", Issuer "www.zefox.org" (not verified))
 by mx1.freebsd.org (Postfix) with ESMTPS id 5BD71765BC
 for <freebsd-arm@freebsd.org>; Mon,  1 Jan 2018 18:10:55 +0000 (UTC)
 (envelope-from fbsd@www.zefox.net)
Received: from www.zefox.net (localhost [127.0.0.1])
 by www.zefox.net (8.15.2/8.15.2) with ESMTPS id w01IAkiW007129
 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO);
 Mon, 1 Jan 2018 10:10:47 -0800 (PST)
 (envelope-from fbsd@www.zefox.net)
Received: (from fbsd@localhost)
 by www.zefox.net (8.15.2/8.15.2/Submit) id w01IAkKX007128;
 Mon, 1 Jan 2018 10:10:46 -0800 (PST) (envelope-from fbsd)
Date: Mon, 1 Jan 2018 10:10:46 -0800
From: bob prohaska <fbsd@www.zefox.net>
To: freebsd-arm@freebsd.org
Subject: Re: Disapearing pl2303 usb serial adapter on rpi2
Message-ID: <20180101181046.GA7042@www.zefox.net>
References: <20171221161120.GA20324@www.zefox.net>
 <dfc17d98-a839-0ab9-2d1b-c47fe26be21e@selasky.org>
 <20171222041657.GA21799@www.zefox.net>
 <20171222173052.GA23984@www.zefox.net>
 <96d7cc41-33bf-1006-54a3-1cc8d9570fd2@selasky.org>
 <20171223001819.GB24362@www.zefox.net>
 <F30A5C4C-E2F4-411E-8BAC-8356C1B985E8@gid.co.uk>
 <20171223173152.GA25961@www.zefox.net>
 <798971d6-54f3-0453-6393-daa79fffd552@selasky.org>
 <20171223191120.GB25961@www.zefox.net>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20171223191120.GB25961@www.zefox.net>
User-Agent: Mutt/1.5.24 (2015-08-30)
X-BeenThere: freebsd-arm@freebsd.org
X-Mailman-Version: 2.1.25
Precedence: list
List-Id: "Porting FreeBSD to ARM processors." <freebsd-arm.freebsd.org>
List-Unsubscribe: <https://lists.freebsd.org/mailman/options/freebsd-arm>,
 <mailto:freebsd-arm-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-arm/>
List-Post: <mailto:freebsd-arm@freebsd.org>
List-Help: <mailto:freebsd-arm-request@freebsd.org?subject=help>
List-Subscribe: <https://lists.freebsd.org/mailman/listinfo/freebsd-arm>,
 <mailto:freebsd-arm-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Mon, 01 Jan 2018 18:10:55 -0000

On Sat, Dec 23, 2017 at 11:11:20AM -0800, bob prohaska wrote:
> 
> Thanks for your attention, and apologies for what's beginning to
> look like  a red herring!
> 

Well, the ungrounded USB shroud wasn't the problem. The pl2303ta locked
up again. Unloading and reloading uplcom didn't help, unplugging the USB 
connector and waiting several minutes didn't help.

However, unplugging the USB connector and plugging it into a powered hub
_with_the_power_off_ did unstick the adapter. Probably the hub loaded down
what little power could backfeed from the downstream serial port to turn
the chip fully off. When reinserted in the RPI2 the adapter was recognized
and seems to be working normally for now.

It's rather clear the pl2303ta is latching up, but why it's worse on a 
-current machine than it is on an 11-stable machine is less obvious. One
difference between the two is USB activity; the -current box uses a USB
flash drive for most of the filesystems, along with a seldom-used mouse 
and keyboard. The -stable machine has all storage on the microSD card, 
no mouse and no keyboard.

Thanks for reading, and any ideas.

bob prohaska