[BRLTTY] brltty causes excessive resume of USB

[Samuel Thibault]

Hello,

We got a bug report in Debian (http://bugs.debian.org/497155):

Frans Pop, le Sat 30 Aug 2008 12:56:42 +0200, a écrit :
> Package: brltty
> Version: 3.10~r3724-1+b1
> Severity: important
> 
> During investigation of an issue with USB in the kernel [1] I found that 
> the USB busses on my system were being activated from suspension way too 
> often. Some debugging identified brltty as the culprit.
> 
> Obviously this is not good for power usage on any system.
> 
> There has to be a better way to check for the presence of a USB brltty 
> device than the current implementation...
> 
> See the attached kernel log (with USB_DEBUG enabled) for the details.
> You will see a huge number of entries like this:
> Aug 30 12:37:18 faramir kernel: usbdev open by brltty
> Aug 30 12:37:18 faramir last message repeated 48 times
> 
> You will also see that it all completely stops at 12:37:30 which is when I 
> did '/etc/init.d brltty stop'.
> 
> Host system: Debian unstable running self-compiled 2.6.27-rc5 kernel
> 
> [1] http://lkml.org/lkml/2008/8/29/311

Do we really need to probe that often?  I guess probing every second
could be enough?

Samuel
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