Clifford
Posts: 30
Joined: Fri May 04, 2012 3:19 pm

Netwok errors in LXDE with USB 1.0 hub

Sun May 27, 2012 10:41 am

I have a problem with very slow network access under very particular but seemingly unrelated conditions.

Using Debian "Squeze" (debian6-19-04-2012):

When running LXDE with keyboard and mouse connected via a self-powered USB 1.0 hub, network access is slow. If I ping my router ping times are all over the place ranging from 1ms to several tens of seconds. On average around 5 seconds but I have seen responses up to 60 seconds.

Outside of LXDE - just plain CLI, the ping times return to normal.

With the keyboard and mouse connected directly to the RPi even in LXDE the ping times return to normal.

I have tried this powered with an after-market Blackberry PSU and from a PC USB port.

I looked in /var/log/messages, and there were many errors like:

smsc95xx 1-1.1:1.0: eth0: Failed to read register index 0x00000114
smsc95xx 1-1.1:1.0: eth0: Failed to read register index 0x00000118

reported ever few seconds. I was hoping to post a log, but the flaky network connection made that impossible. Now I have found that it is stable without the USB hub, I may try again if the information might prove useful.

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jbeale
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Contact: Website

Re: Netwok errors in LXDE with USB 1.0 hub

Sun May 27, 2012 3:04 pm

Do you have access to a multimeter? While experiencing the error, can you check the voltage between TP1 and TP2 as shown here?
http://elinux.org/R-Pi_Troubleshooting# ... r_problems

Your symptoms match a low voltage problem. Even if your USB charger is OK, there may be, for example, a high resistance power input polyfuse (F3 on the bottom side of the board) which is giving you issues.

My theory is that running the windowing system causes higher processor load, which draws more current, which lowers the onboard voltage causing the USB/Ethernet chip to start flaking out. That chip usually dies first, because it needs 3.3V from a linear regulator having a large dropout voltage, whereas the main SoC chip has its own switching regulator running from the +5V supply to generate 1.8V and that switcher can work with lower input voltage.

Clifford
Posts: 30
Joined: Fri May 04, 2012 3:19 pm

Re: Netwok errors in LXDE with USB 1.0 hub

Sun May 27, 2012 6:40 pm

Thanks @jbeale. Sounds plausible; the power supply is underrated at 580mA - my purchasing error! I loaned my multimeter sometime ago and have not seen it since.

I was hoping that using a powered USB hub would not impose an added load - in fact I assumed it would reduce the load by not having both the mouse and keyboard powered by the RPi, yet it works fine in that configuration. It was an old hub I had lying around. I was only using it because I wanted to free up a port to try to get my Edimax Nano WiFi working. My original plan was to use an old Cherry wireless keyboard and mouse I had lying around so they only required one port for the wireless receiver, but somehow I have mislaid the mouse so had to use a wired one.

Anyhow, the new plan is to get a wireless keyboard with a trackpad which will make much more sense in the living room attached to the TV since it will not then require a mousing surface. My TV has USB ports, so it would be convenient if these were man enough to drive the RPi; it know it will power a 2.5" USB drive - I'll get a multimeter for that, and in the meantime a higer-rated PSU in any case.

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usbspyder
Posts: 6
Joined: Wed May 30, 2012 8:45 pm

Re: Netwok errors in LXDE with USB 1.0 hub

Wed May 30, 2012 8:56 pm

Posting just for future reference by others, as it sounds as if you have the solution already.

Had exactly the same problem. Bought a USB power supply from maplin, rated at 1A. All was going well until i plugged in Msoft wireless mouse which caused USB and eth0 problems in the logs :

usb 1-1.2: reset full speed USB device number 4 using dwc_otg
smsc95xx 1-1.1:1.0: eth0: Failed to read register index 0x00000114

Unplugging the mouse removed the errors completely.

Clifford
Posts: 30
Joined: Fri May 04, 2012 3:19 pm

Re: Netwok errors in LXDE with USB 1.0 hub

Wed May 30, 2012 10:35 pm

@usbspyder

I now have the RPi working with a Logitech K400 wireless keboard/trackpad and an Edimax Nano USB WiFi. I had a lot of trouble getting it to work, but used @MrEngman's script at http://www.raspberrypi.org/phpBB3/viewt ... =26&t=6256. It took a few attempts. I had to let the script run with a wired keyboard and no Ethernet, but once installed it runs with WiFi and the wireless keyboard. I imaged the card once I had a working configuration - I've had to start again too many times!

The script failed to complete the part where it run's Hexxeh's rpi-update, but when I did that manually afterward the WiFi stopped working. That may explain why I had so much trouble doing it manually since I had run rpi-update before attempting to get WiFi working.

The keyboard becomes a bit unreliable especially when in the web-browser, and I think that this is still a power supply issue. I bought a new supply nominally rated at 1A, but it is worse than the original 500mA rated one! My son's phone has a 700mA rated supply, and that performs pretty much as well as the 500mA. The rating on the plate I think is not always to be believed it seems.

Anyway both USB devices are tiny, so make a neat package. The K400 keyboard is about the size, build quality, and similar in appearance to a ZX Spectrum+, which is cool, but not a compliment build quality wise!

marsman2020
Posts: 72
Joined: Sun May 20, 2012 11:26 pm

Re: Netwok errors in LXDE with USB 1.0 hub

Thu May 31, 2012 5:37 pm

Clifford - are you now running the 2 USB devices directly off the Pi with no powered hub??

There is an issue folks are trying to investigate where hubs seem to kill the Ethernet and/or wifi when LXDE is run...

Clifford
Posts: 30
Joined: Fri May 04, 2012 3:19 pm

Re: Netwok errors in LXDE with USB 1.0 hub

Thu May 31, 2012 7:40 pm

marsman2020 wrote:Clifford - are you now running the 2 USB devices directly off the Pi with no powered hub??
Yes but only just, the keyboard/trackpad tends to drop-out especially in the web-browser. I still don't have a suitable PSU though. I have an old powered USB 1.0 hub on which I tried to use the keyboard dongle, but with the hub plugged in the RPi would not boot, or at least issues a large number of USB enumeration errors and the like on boot up.
marsman2020 wrote:There is an issue folks are trying to investigate where hubs seem to kill the Ethernet and/or wifi when LXDE is run...
Never got that far with this hub!

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