Category: PC Tweakage

For the last few months, one of the USB hubs in my PC has been disabling a port connected to an external USB hub. The external hub re-establishes communication with all the devices, but the X server doesn’t take kindly to having devices yanked out from underneath it. After this glitch, my left-hand trackball and tablet are dead in the water; the only way to get ’em working is to log out, restart X, and log back in again. Not pleasant.

Oddly, the keyboard continues to function.

Note that it’s the hub in the PC that’s complaining, not the external hub.

I’ve tweaked the obvious things: switched USB ports on the PC, replaced the external hub, powered and un-powered the external hub, rearranged the devices on the hub, moved other devices away from the hub, and so forth and so on.

Now it’s time to start taking notes. The current external hub is a cheap, no-name gadget direct from China that bears a striking resemblance to the tchotchke HP-branded “Made In China” hub a friend picked up at SC06.

Both hubs have a cut-out in the case for a power plug, but the internal circuit boards lack the requisite jack to actually make use of external power.

Here’s the current dmesg dump.

[ 2917.702975] hub 1-0:1.0: port 2 disabled by hub (EMI?), re-enabling...
[ 2917.702986] usb 1-2: USB disconnect, address 3
[ 2917.702989] usb 1-2.2: USB disconnect, address 4
[ 2917.712300] /build/buildd/linux-2.6.24/drivers/input/tablet/wacom_sys.c: wacom_sys_irq - usb_submit_urb failed with result -19
[ 2917.787223] usb 1-2.3: USB disconnect, address 5
[ 2917.831161] usb 1-2.4: USB disconnect, address 6
[ 2918.002420] usb 1-2: new full speed USB device using uhci_hcd and address 7
[ 2918.165658] usb 1-2: configuration #1 chosen from 1 choice
[ 2918.170675] hub 1-2:1.0: USB hub found
[ 2918.172533] hub 1-2:1.0: 4 ports detected
[ 2918.502967] usb 1-2.2: new low speed USB device using uhci_hcd and address 8
[ 2918.662816] usb 1-2.2: configuration #1 chosen from 1 choice
[ 2918.679915] input: Microsoft Comfort Curve Keyboard 2000 as /devices/pci0000:00/0000:00:1d.0/usb1/1-2/1-2.2/1-2.2:1.0/input/input10
[ 2918.721211] input,hidraw2: USB HID v1.11 Keyboard [Microsoft Comfort Curve Keyboard 2000] on usb-0000:00:1d.0-2.2
[ 2918.751759] input: Microsoft Comfort Curve Keyboard 2000 as /devices/pci0000:00/0000:00:1d.0/usb1/1-2/1-2.2/1-2.2:1.1/input/input11
[ 2918.793088] input,hidraw3: USB HID v1.11 Device [Microsoft Comfort Curve Keyboard 2000] on usb-0000:00:1d.0-2.2
[ 2919.010108] usb 1-2.3: new low speed USB device using uhci_hcd and address 9
[ 2919.165963] usb 1-2.3: configuration #1 chosen from 1 choice
[ 2919.187020] input: Kensington      Kensington Expert Mouse as /devices/pci0000:00/0000:00:1d.0/usb1/1-2/1-2.3/1-2.3:1.0/input/input12
[ 2919.244778] input,hidraw4: USB HID v1.10 Mouse [Kensington      Kensington Expert Mouse] on usb-0000:00:1d.0-2.3
[ 2919.465338] usb 1-2.4: new low speed USB device using uhci_hcd and address 10
[ 2919.617208] usb 1-2.4: configuration #1 chosen from 1 choice
[ 2919.625530] input: Wacom Graphire3 6x8 as /devices/pci0000:00/0000:00:1d.0/usb1/1-2/1-2.4/1-2.4:1.0/input/input13

The external hub is on the white cable (a USB extender cable, which may contribute to the problem) plugged into the port at the far right from the network cable. But i’ve used an external hub with a different and very official USB A-B cable.

The USB connections on the back panel:

Top row: Zire 71 PDA cradle | External USB hub (the offending one)

Bottom Row: Logitech trackball | Dell 2001 monitor hub | empty port

What I changed after this glitch:

HP SC06 hub replaces no-name hub.

Update: Time passes… and it craps out twice.

The dmesg dump:

[10625.203907] usb 1-2.2: USB disconnect, address 8
[10625.970605] usb 1-2.3: USB disconnect, address 9
[10626.865087] usb 1-2.4: USB disconnect, address 10
[10627.880887] usb 1-2: USB disconnect, address 7
[10638.410365] usb 1-2: new full speed USB device using uhci_hcd and address 11
[10638.579231] usb 1-2: configuration #1 chosen from 1 choice
[10638.582167] hub 1-2:1.0: USB hub found
[10638.584118] hub 1-2:1.0: 4 ports detected
[10638.898574] usb 1-2.1: new low speed USB device using uhci_hcd and address 12
[10639.035458] usb 1-2.1: configuration #1 chosen from 1 choice
[10639.038484] input: Wacom Graphire3 6x8 as /devices/pci0000:00/0000:00:1d.0/usb1/1-2/1-2.1/1-2.1:1.0/input/input14
[10639.301891] usb 1-2.3: new low speed USB device using uhci_hcd and address 13
[10639.445768] usb 1-2.3: configuration #1 chosen from 1 choice
[10639.466865] input: Microsoft Comfort Curve Keyboard 2000 as /devices/pci0000:00/0000:00:1d.0/usb1/1-2/1-2.3/1-2.3:1.0/input/input15
[10639.505029] input,hidraw2: USB HID v1.11 Keyboard [Microsoft Comfort Curve Keyboard 2000] on usb-0000:00:1d.0-2.3
[10639.525686] input: Microsoft Comfort Curve Keyboard 2000 as /devices/pci0000:00/0000:00:1d.0/usb1/1-2/1-2.3/1-2.3:1.1/input/input16
[10639.572404] input,hidraw3: USB HID v1.11 Device [Microsoft Comfort Curve Keyboard 2000] on usb-0000:00:1d.0-2.3
[10639.777083] usb 1-2.4: new low speed USB device using uhci_hcd and address 14
[10639.917975] usb 1-2.4: configuration #1 chosen from 1 choice
[10639.934026] input: Kensington      Kensington Expert Mouse as /devices/pci0000:00/0000:00:1d.0/usb1/1-2/1-2.4/1-2.4:1.0/input/input17
[10639.971692] input,hidraw4: USB HID v1.10 Mouse [Kensington      Kensington Expert Mouse] on usb-0000:00:1d.0-2.4
[10962.110496] usb 5-5.2: new high speed USB device using ehci_hcd and address 8
[10962.219819] usb 5-5.2: configuration #1 chosen from 1 choice
[12290.756701] usb 5-5.2: USB disconnect, address 8
[54272.946992] hub 1-0:1.0: port 2 disabled by hub (EMI?), re-enabling...
[54272.947001] usb 1-2: USB disconnect, address 11
[54272.947003] usb 1-2.1: USB disconnect, address 12
[54273.003212] usb 1-2.3: USB disconnect, address 13
[54273.071171] usb 1-2.4: USB disconnect, address 14
[54273.214485] usb 1-2: new full speed USB device using uhci_hcd and address 15
[54273.383873] usb 1-2: configuration #1 chosen from 1 choice
[54273.386778] hub 1-2:1.0: USB hub found
[54273.388736] hub 1-2:1.0: 4 ports detected
[54273.699213] usb 1-2.1: new low speed USB device using uhci_hcd and address 16
[54273.840096] usb 1-2.1: configuration #1 chosen from 1 choice

So replacing the hub seems to have not done anything useful, as expected.

Next step: plug the hub cable into the right-hand port on the bottom row.

Update: Time passes and another disconnect pops up. I’d just poked the USB button on my pocket camera’s cradle. Coincidence? Sometimes it disconnects when I sit down, which suggests a static discharge.

The dmesg dump:

[ 1275.088536] hub 3-0:1.0: port 2 disabled by hub (EMI?), re-enabling...
[ 1275.088547] usb 3-2: USB disconnect, address 5
[ 1275.088549] usb 3-2.1: USB disconnect, address 6
[ 1275.132321] usb 3-2.3: USB disconnect, address 7
[ 1275.220223] usb 3-2.4: USB disconnect, address 8
[ 1275.371502] usb 3-2: new full speed USB device using uhci_hcd and address 9
[ 1275.541198] usb 3-2: configuration #1 chosen from 1 choice
[ 1275.544148] hub 3-2:1.0: USB hub found
[ 1275.546102] hub 3-2:1.0: 4 ports detected
[ 1275.856554] usb 3-2.1: new low speed USB device using uhci_hcd and address 10
[ 1275.993439] usb 3-2.1: configuration #1 chosen from 1 choice
[ 1275.997194] input: Wacom Graphire3 6x8 as /devices/pci0000:00/0000:00:1d.2/usb3/3-2/3-2.1/3-2.1:1.0/input/input10
[ 1276.259871] usb 3-2.3: new low speed USB device using uhci_hcd and address 11
[ 1276.406735] usb 3-2.3: configuration #1 chosen from 1 choice
[ 1276.423836] input: Microsoft Comfort Curve Keyboard 2000 as /devices/pci0000:00/0000:00:1d.2/usb3/3-2/3-2.3/3-2.3:1.0/input/input11
[ 1276.469640] input,hidraw2: USB HID v1.11 Keyboard [Microsoft Comfort Curve Keyboard 2000] on usb-0000:00:1d.2-2.3
[ 1276.490647] input: Microsoft Comfort Curve Keyboard 2000 as /devices/pci0000:00/0000:00:1d.2/usb3/3-2/3-2.3/3-2.3:1.1/input/input12
[ 1276.545539] input,hidraw3: USB HID v1.11 Device [Microsoft Comfort Curve Keyboard 2000] on usb-0000:00:1d.2-2.3
[ 1276.746036] usb 3-2.4: new low speed USB device using uhci_hcd and address 12
[ 1276.896906] usb 3-2.4: configuration #1 chosen from 1 choice
[ 1276.912985] input: Kensington      Kensington Expert Mouse as /devices/pci0000:00/0000:00:1d.2/usb3/3-2/3-2.4/3-2.4:1.0/input/input13
[ 1276.960781] input,hidraw4: USB HID v1.10 Mouse [Kensington      Kensington Expert Mouse] on usb-0000:00:1d.2-2.4
[ 1280.734257] usb 5-5.2: new high speed USB device using ehci_hcd and address 7
[ 1280.843575] usb 5-5.2: configuration #1 chosen from 1 choice

Next step: rearrange cables thusly…

Top row: Zire 71 PDA cradle | Dell 2001 monitor hub

Bottom Row: Logitech trackball | External USB hub (the offending one) | empty port

Methinks it’s time to start yanking the SD card out of the camera and poking it into the PC’s media reader. That should eliminate one possible source of bus confusion.

Time to reset…

Update: time passes and it’s been working OK… up until I zapped the desk lamp with a teeny static spark, at which moment dmesg reports this:

[49077.518404] hub 3-0:1.0: port 1 disabled by hub (EMI?), re-enabling...
[49077.518413] usb 3-1: USB disconnect, address 2
[49077.518416] usb 3-1.1: USB disconnect, address 3
[49077.562470] usb 3-1.3: USB disconnect, address 4
[49077.658411] usb 3-1.4: USB disconnect, address 5
[49077.805865] usb 3-1: new full speed USB device using uhci_hcd and address 6
[49077.974924] usb 3-1: configuration #1 chosen from 1 choice
[49077.982443] hub 3-1:1.0: USB hub found
[49077.983860] hub 3-1:1.0: 4 ports detected
[49078.302253] usb 3-1.1: new low speed USB device using uhci_hcd and address 7
[49078.439141] usb 3-1.1: configuration #1 chosen from 1 choice
[49078.442156] input: Wacom Graphire3 6x8 as /devices/pci0000:00/0000:00:1d.2/usb3/3-1/3-1.1/3-1.1:1.0/input/input10
[49078.709567] usb 3-1.3: new low speed USB device using uhci_hcd and address 8
[49078.853443] usb 3-1.3: configuration #1 chosen from 1 choice
[49078.875540] input: Microsoft Comfort Curve Keyboard 2000 as /devices/pci0000:00/0000:00:1d.2/usb3/3-1/3-1.3/3-1.3:1.0/input/input11
[49078.920499] input,hidraw2: USB HID v1.11 Keyboard [Microsoft Comfort Curve Keyboard 2000] on usb-0000:00:1d.2-1.3
[49078.941372] input: Microsoft Comfort Curve Keyboard 2000 as /devices/pci0000:00/0000:00:1d.2/usb3/3-1/3-1.3/3-1.3:1.1/input/input12
[49078.999851] input,hidraw3: USB HID v1.11 Device [Microsoft Comfort Curve Keyboard 2000] on usb-0000:00:1d.2-1.3
[49079.212710] usb 3-1.4: new low speed USB device using uhci_hcd and address 9
[49079.351593] usb 3-1.4: configuration #1 chosen from 1 choice
[49079.367726] input: Kensington      Kensington Expert Mouse as /devices/pci0000:00/0000:00:1d.2/usb3/3-1/3-1.4/3-1.4:1.0/input/input13
[49079.411112] input,hidraw4: USB HID v1.10 Mouse [Kensington      Kensington Expert Mouse] on usb-0000:00:1d.2-1.4

So it looks like there’s really something EMI-ish going on. Perhaps it’s time to look into grounding all the exposed metal around here.

Update: It really was static electricity. More discussion there.

Flash is one of those things that comes heartbreakingly close to actually working, particularly in a 64-bit Linux OS. There’s an intricate scaffolding that plugs the 32-bit Flash code into the 64-bit Firefox superstructure, but …

Worse, there’s an error in the Hardy Flash 10 repository entry that points to a nonexistent Macromedia download website, so all the usual hints & tips don’t work. That seems to have broken in December and the automatic installation fails quietly. Using sudo apt-get update flashplugin-nonfree reveals the problem.

Unfortunately, the sum total of all my fiddling was a Flash installation that sorta-kinda worked, with a significantly flaky crust.

What works slightly better: force the version to Flash 9 by pinning the flashplugin-nonfree package version in apt-get. Start by removing everything related to Flash. Then, with a clean slate, this post on the Ubuntu forums shows how to get a clean installation:

1.) Create /etc/apt/preferences with this entry:

Explanation: Flash plugin from hardy-backports was broken on 12/24/2008;
Explanation: pinning to hardy-updates for now until it is fixed
Package: flashplugin-nonfree
Pin: release a=hardy-updates
Pin-Priority: 980

2.) sudo apt-get update

3.) sudo apt-get install flashplugin-nonfree

4.) Restart Firefox

It still gives me a blank gray background where the Flash should appear, which is sometimes cured by reloading the page, but it seems more stable.

Adobe has a genuine 64-bit Flash alpha out, but (as of the 16 December 2008 version) it reliably crashes on sites I really care about. Like, for example, nytimes.com.

Memo to self: un-pin this in a few months and see what happens.

Update: It still jams up with gray screens where Flash should be, no matter what I do.

In the process of setting up a new PC for my mother, I finally figured out how to get remote desktop sharing in Kubuntu Hardy working. You’d think the bog-standard (and default) krfb would work, but it crashed every time. Come to find out, after much searching, the solution boils down to this…

Shoot krfb in the head, use vnc4server and x11vnc.

Use synaptic or apt-get to install those and all their dependencies on the remote machine (i.e., the one that will become my mother’s PC). While you’re at it, uninstall krfb: good riddance.

Run vncpasswd and feed in an appropriate password that you’ll use to authorize yourself to the vnc session.

Log out, restart X (with Ctrl-Alt-Backspace, perhaps), log back in again to get all the X11 infrastructure up to speed.

On your local machine (i.e., mine), use SSH to sign in to the remote box:

ssh -p unusual-port -L 5900:localhost:5900 remote.PC.ip.addr

The -L creates a tunnel from your local machine’s port 5900 to the remote machine’s port 5900, through the authorized SSH session.

I use an unusual port because running SSH on port 22 on an internet-facing machine (even behind a firewall router) is just plain dumb. I doubt the unusual port provides much protection, but it should shake off a few script kiddies.

[Update: Just in case you regard shared-key authorization and a nonstandard port as evidence of clinical paranoia, read that. One of the comments notes that using a nonstandard port gets rid of all the low-speed zombies…]

Incidentally, the firewall router must forward the unusual port directly to the PC’s local IP address, which requires a bit of tweakage all by itself; that depends on which router you have. Word to the wise: do not use DHCP to get the PC’s IP address. Think about it.

That PC is also set up with my RSA keys, so that the kiddies can’t brute-force a username / password login attack. And, yes, I regenerated the keys after the Debian goof.

This is still on my LAN, so I use a dotted quad IP address (being too lazy to tweak /etc/hosts for a temporary machine), but you can use the host name maintained by DynDNS or their ilk for a truly remote box. See this post for the straight dope on making that work.

Then fire up a remote-desktop client like, for example, krdc on your local PC, with the “remote desktop” address aimed at:

localhost:5900

That’s the local end of the SSH tunnel to the remote PC. It won’t work if you aim it at the remote machine’s IP address, because it’s not watching for incoming connections (nor is the router forwarding them).

Type in the password and shazam you should see whatever’s appearing on the remote desktop. Mouse & keyboard control should work just fine, too. Word to the wise: make sure your local monitor is bigger than the remote monitor; while you can scroll around or scale what you see, that’s icky.

It should be obvious that you cannot “switch users” to a different X console on the remote box and expect it to work. I tried it, just for grins, and it doesn’t. You could probably tunnel another session in through port 5901 (or 5900 + whatever the X11 console might be), but I haven’t tried that.

Last year I set my mother up with Verizon’s cheapest DSL service: 768 kb/s down and 16 kb/s up, all for a whopping 15 bucks plus tax a month. Yes, that’s 16 kb/s: slower than old-school dial-up modems. Sheesh & similar remarks. So all this fancy remote-desktop GUI stuff won’t work for diddly with the PC in her apartment.

SSH and the command line rule!

For some unknown reason, Kubuntu 8.04 doesn’t create a /dev/scanner link while it’s figuring out all the SCSI devices. I wanted to make the link sort of generic for any scanner that I might plug in, but I had to settle for a unique udev match.

The scanner popped out of udev as /dev/sg5 this time and

udevinfo --query=all --attribute-walk --name=/dev/sg5

emits this useful chunk:

looking at parent device '/devices/pci0000:00/0000:00:1e.0/0000:05:05.0/host4/target4:0:2/4:0:2:0':
    KERNELS=="4:0:2:0"
    SUBSYSTEMS=="scsi"
    DRIVERS==""
    ATTRS{device_blocked}=="0"
    ATTRS{type}=="3"
    ATTRS{scsi_level}=="3"
    ATTRS{vendor}=="HP      "
    ATTRS{model}=="C7670A          "
    ATTRS{rev}=="3945"
    ATTRS{state}=="running"
    ATTRS{timeout}=="0"
    ATTRS{iocounterbits}=="32"
    ATTRS{iorequest_cnt}=="0x656"
    ATTRS{iodone_cnt}=="0x656"
    ATTRS{ioerr_cnt}=="0x2"
    ATTRS{modalias}=="scsi:t-0x03"
    ATTRS{evt_media_change}=="0"
    ATTRS{queue_depth}=="2"
    ATTRS{queue_type}=="none"

Plucking the readable bits out produces this stanza for/etc/udev/rules.d/60-symlinks.rules

#-- hack to create /dev/scanner
SUBSYSTEMS=="scsi", ATTRS{vendor}=="HP", ATTRS{model}=="C7670A", SYMLINK+="scanner"

Then you can use that to fire up xsane thusly:

sane hp:/dev/scanner

With that in hand, edit GIMP’s ~/.gimp-whatever/menurc and ~/.gimp-whatever/pluginrc to replace sg5 (or whatever) with scanner.

Works like a champ…

The straight dope on writing udev rules is at http://www.reactivated.net/writing_udev_rules.html

Memo to self: there’s got to be a way to make this generic, perhaps by piggybacking on whatever udev stanza assigns the scanner group to that /dev/sg? device.

Update: make sure you’re in the scanner group

sudo usermod -a -G scanner username