Date: Thu, 21 Dec 2017 08:19:43 -0800 (PST) From: "Rodney W. Grimes" <freebsd-rwg@pdx.rh.CN85.dnsmgr.net> To: bob prohaska <fbsd@www.zefox.net> Cc: "Jukka A. Ukkonen" <jau789@gmail.com>, freebsd-arm@freebsd.org Subject: Re: Disapearing pl2303 usb serial adapter on rpi2 Message-ID: <201712211619.vBLGJhpM032044@pdx.rh.CN85.dnsmgr.net> In-Reply-To: <20171221161120.GA20324@www.zefox.net>
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> On Wed, Dec 20, 2017 at 09:13:12PM +0200, Jukka A. Ukkonen wrote: > > On 12/20/17 19:02, bob prohaska wrote: > > > On an RPI2 at r326951 a pl2303 usb-serial adapter seems to be locking up > > > after a few hours. In the past this could be rectified by using usbconfig > > > to power cycle it, but now even that doesn't work. Apart from the serial > > > device file vanishing from /dev there seems to be no other ill effect. > > > Rebooting fixes the problem for minutes to hours. > > > > > > There is no explict error report in dmesg, but when usbconfig tries to power > > > cycle the adapter the console reports: > > > > > > uhub_explore_handle_re_enumerate: Could not unconfigure device (ignored) > > > usbd_req_re_enumerate: addr=9, set address failed! (USB_ERR_IOERROR, ignored) > > > usbd_setup_device_desc: getting device descriptor at addr 9 failed, USB_ERR_IOERROR > > > usbd_req_re_enumerate: addr=9, set address failed! (USB_ERR_STALLED, ignored) > > > usbd_setup_device_desc: getting device descriptor at addr 9 failed, USB_ERR_STALLED > > > > > > > > > A second RPI2 running r326747 is subject to the same lockup, but the adapter > > > can be unstuck using usbconfig to power cycle it. > > > > > > > > > Are there any diagnostics which could shed more light on the problem? > > > > > > Thanks for reading, > > > > > > bob prohaska > > > > > > _______________________________________________ > > > freebsd-arm@freebsd.org mailing list > > > https://lists.freebsd.org/mailman/listinfo/freebsd-arm > > > To unsubscribe, send any mail to "freebsd-arm-unsubscribe@freebsd.org" > > > > > > > > > > > > > So, my guess is that the poor RPI is unable to drive enough power > > to your pl2303. Esp. when there are multiple USB devices draining > > power you will eventually exceed the RPI's power output capacity. > > As a result you will see a magically vanishing and reappearing USB > > device. > > The Pi is on a 2.5 amp power supply, the other usb loads are a keyboard, > mouse and USB flash drive, so it's unlikely to be a power issue. The problem > seems to have gotten worse with the latest -current, which is what motivated > my post. It's been suggested to simply give up on pl2303 devices and use > ftdi but I've resisted the urge because the pl2303 adapters work fine on > Mac OS and Raspbian. > > The adapters work correctly with Prolific's drivers and are not identified > as impostors. Testing disclosed that unpowering the USB end of the adapter > does not suffice to unstick it, but unpowering both ends does allow it to > reset. Hopefully it's an initialization issue. What do you mean by unpowering both ends? If this is one of the serial adapters that has a power pin to plug in with the Gnd/Rx/Tx pins I would highly recommend you leave that power pin disconnected as connecting it can lead to power supplies in parallel and "that is a bad thing". > Thanks for reading! > > bob prohaska > -- Rod Grimes rgrimes@freebsd.org
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