USB braille display no longer starts with brltty

[Mike Pedersen]

I have connected a Baum Super Vario braille display to the USB port of my laptop. When I boot feisty I hear the tone telling me the the display is attempting to initialize just as the GDM login is appearing. After about 2 seconds I then hear the tone telling me that the connection to the display has been terminated. At no point do I ever see data on the braille display. If I then switch to a terminal and attempt to start rltty manually I repeatedly hear the initialization and shutdown tones until I kill the brltty process. This system is configured with all stock feisty packages, I have not attempted to build brltty from svn. Manually. Starting brltty with this braille display works with out a problem on both of my edgy systems. This problem happenns with multiple installs of the feisty daily live CD including the one from January 20th. Please let me know what log files I should include here to help resolve the problem.

[Henrik Nilsen Omma (henrik)]

Mike, a copy of /var/log/syslog from when this happens might be useful.

[Mike Pedersen (michael-pedersen)]

Here is the requested syslog. Note that I killed the brltty process after it attempted to initialize several times.

[Henrik Nilsen Omma (henrik)]

Thanks Mike. Hm, interesting looks like it's interfering with Network Manager somehow. -- A new feature in Feisty.

I'll add a bug task for NM so the maintainers of that will have a look. In the meantime, Mike: could you try uninstalling network-manager and see if that helps?

[Mike Pedersen (michael-pedersen)]

Hi Henrik,
> Thanks Mike. Hm, interesting looks like it's interfering with
> Network Manager somehow. -- A new feature in Feisty.
>
> I'll add a bug task for NM so the maintainers of that will
> have a look.
> In the meantime, Mike: could you try uninstalling
> network-manager and see if that helps?
>
I'm reluctant to do this as the removal also wants to remove ubuntu-desktop.

Mike

[Henrik Nilsen Omma (henrik)]

Hi Mike,

ubuntu-desktop is just a meta package that causes other packages to be installed/removed. You can safely remove it for the purposes of testing whether this works. It won't remove the entire ubuntu desktop as such. However for the long term it will cause issues with upgading, so it should be installed again.

It's just the easiest way of figuring out whether network-manager is the culprit so I can know who to follow this issue up with. Another option would be to find some other way to disable network-manager.

Of course the real goal is making both n-m and USB braille play nicely together without such hacks; this is just fault searching.

[Mike Pedersen (michael-pedersen)]

Hi Henrik, removing the network manager and rebooting made no difference with this problem.

[Henrik Nilsen Omma (henrik)]

Thanks. OK passing it over to the kernel team. It seems the kernel disables the USB device just after brltty tries to use it. See the last line in the log clipping below:

Feb 1 10:50:00 laptop brltty[5861]: starting.
Feb 1 10:50:00 laptop brltty[5861]: BRLTTY 3.7.2
Feb 1 10:50:00 laptop brltty[5878]: Linux Screen Driver
Feb 1 10:50:00 laptop brltty[5878]: Creating directory: /etc/brltty/usbfs
Feb 1 10:50:00 laptop brltty[5878]: Mounting USBFS: /etc/brltty/usbfs
Feb 1 10:50:00 laptop kernel: [ 138.396000] usb 3-1: USB disconnect, address 3

[Henrik Nilsen Omma (henrik)]

Oops, wrong kernel version. Sorry.

[Ben Collins (ben-collins)]

Can you unload the ehci_hcd driver and see if this helps?

It looks like brltty is causing some USB resets, or is resetting the device...I'm not sure this is a kernel bug, because it may be brltty doing something wrong to cause these resets.

[Ben Collins (ben-collins)]

Also, try booting to a 2.6.17 edgy kernel with feisty userspace and see if that fixes it.

[Mike Pedersen (michael-pedersen)]

If you can give me more detailed information on what you are asking I can give this a try. Note that the same braille display and the same version of brltty work just fine on an edgy system.

[Ben Collins (ben-collins)]

Run:

sudo modprobe ehci_hcd

After that, see if restarting brltty works.

Also, please see about install linux-image-2.6.17-10-generic from edgy, and booting that on the feisty system. I understand that the version is the same on edgy, so it's unlikely to fix the problem, but there's always the small chance that brltty compiled against feisty has causing some issues.

Thanks

[Mike Pedersen (michael-pedersen)]

The "sudo modprobe ehci_hcd" made no difference. When I tried to restart brltty I got the same result. I also just tried the latest brltty sources from head with the same result.
If it would help, perhaps I could allow you to ssh into a machine that exhibits the problem. I'm normally not into opening ports but for abit of testing it should be OK.

[Ben Collins (ben-collins)]

On Wed, 2007-02-07 at 19:42 +0000, Mike Pedersen wrote:
> The "sudo modprobe ehci_hcd" made no difference. When I tried to restart brltty I got the same result. I also just tried the latest brltty sources from head with the same result.
> If it would help, perhaps I could allow you to ssh into a machine that exhibits the problem. I'm normally not into opening ports but for abit of testing it should be OK.

My mistake, use "sudo modprobe -r ehci_hcd"

[Mike Pedersen (michael-pedersen)]

> My mistake, use "sudo modprobe -r ehci_hcd"
>
Sadly nothing has changed.
Mike

[Mike Pedersen (michael-pedersen)]

An interesting new development here. Within the past half hour a new version of brltty was uploaded and added to udev to support the auto detection of braille displays on boot up. Braille now starts successfully for me. A couple small problems remain though:
1. brltty attempted to start twice which made an error appear on the braille display. A press of any key on the braille display dismissed the error.
2. Orca is not currently communicating with brltty so I am currently only able to read text consoles with brltty. This problem could however be a configuration error on my part so I'll give more info when I have it.

[Henrik Nilsen Omma (henrik)]

Yay, progress!

I'm closing this as fixed since the problem is clearly much reduced, and I'm opening a new bug 83939 for the two issues you mentioned.