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

On Sun, 10 Aug 2008 04:08:37 +0100 Aivils Stoss wrote:

On Saturday 09 August 2008 11:42:26 am Samuel Thibault wrote:

quoted

Aivils Stoss, le Fri 08 Aug 2008 07:02:24 +0100, a écrit :

quoted

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.


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