Re: PROBLEM: USB keyboards works only 4 per PC host port

[Aivils Stoss]

On Friday 15 August 2008 7:19:48 am Randy Dunlap wrote:
> On Sun, 10 Aug 2008 04:08:37 +0100 Aivils Stoss wrote:
> > On Saturday 09 August 2008 11:42:26 am Samuel Thibault wrote:
> > > Aivils Stoss, le Fri 08 Aug 2008 07:02:24 +0100, a écrit :
> > > > I suppose this is Linux kernel bug because i test keyboards under
> > > > Windows, which support any schema of cascading of usb hubs.
> > >
> > > On the very same machine and hubs?
> >
> > Yes, on same machine. Under Windows i don't have evdev interface,
> > checked only how keypress go to console.
> > Of course to repeat a try You must have at least 5 keyboards and
> > 1 7-port or 2 4-port hubs and kernel 2.6.22 and above. I allways
> > got result - 5th, 6th, 7th keyboard does not send events to console
> > or evdev.
>
> [adding linux-usb mailing list]
>
> Hi,
>
> I finally got 5 USB keyboards together along with 2 hubs.
> I daisy-chained the hubs and connected 1 keyboard to the hub that is
> on the notebook computer USB port, then I connected 4 keyboards to the
> second hub.  They all worked for me, meaning that I can type on all of
> them and have their characters show up on my console.
>
> I'm testing with 2.6.7-rc2.
> 'usbtree' output of the USB subsystem is attached.

Yeah! 2.6.7 is a bit obsolete. At my end 2.6.15 support more than 4
keyboards per PC port , but mess up input when is plugged more than
9 keyboards. 10th is capable to send keypress events, but last pressed
key will be repeated until ctrl-c . 10th keyboard disturb an auto repeat of 
all keyboards.

Aivils

>
>
> ---
> ~Randy
> Linux Plumbers Conference, 17-19 September 2008, Portland, Oregon USA
> http://linuxplumbersconf.org/


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