From: Randy Dunlap <rdunlap@xenotime.net>
To: Aivils Stoss <aivils@latnet.lv>
Cc: lud <linux-usb@vger.kernel.org>,
Samuel Thibault <samuel.thibault@ens-lyon.org>,
linux-input@vger.kernel.org, jkosina@suse.cz,
linux-kernel@vger.kernel.org,
linuxconsole-dev@lists.sourceforge.net
Subject: Re: PROBLEM: USB keyboards works only 4 per PC host port
Date: Mon, 18 Aug 2008 08:14:32 -0700 [thread overview]
Message-ID: <20080818081432.782d9632.rdunlap@xenotime.net> (raw)
In-Reply-To: <200808181642.49489.aivils@latnet.lv>
On Mon, 18 Aug 2008 16:42:49 +0530 Aivils Stoss wrote:
> 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.
Sorry, my keyboard made a typo. I'm testing with 2.6.27-rc2.
So the problem is now different from your original report, right?
What speed is the host port that the keyboards are connected to?
Could it be a USB bus bandwidth limitation? (not that any code
checks for that)
I barely found 5 USB keyboards, so I surely can't test 10 or more. ;)
I suppose that it will take some USB debug messages to attempt to see
what is going on...
---
~Randy
Linux Plumbers Conference, 17-19 September 2008, Portland, Oregon USA
http://linuxplumbersconf.org/
next prev parent reply other threads:[~2008-08-18 15:14 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-08-08 6:02 PROBLEM: USB keyboards works only 4 per PC host port Aivils Stoss
2008-08-09 10:42 ` Samuel Thibault
2008-08-10 3:08 ` Aivils Stoss
2008-08-15 1:49 ` Randy Dunlap
2008-08-18 11:12 ` Aivils Stoss
2008-08-18 15:14 ` Jiri Kosina
2008-08-18 15:14 ` Randy Dunlap [this message]
2008-08-19 9:57 ` Aivils Stoss
2008-08-19 15:03 ` Alan Stern
2008-08-19 15:19 ` Randy Dunlap
2008-08-19 15:23 ` Jiri Kosina
2008-08-19 17:55 ` Dmitry Torokhov
2008-08-20 5:40 ` Aivils Stoss
-- strict thread matches above, loose matches on Subject: below --
2008-08-19 21:06 juanslayton
2008-08-19 16:40 juanslayton
2008-08-19 18:21 ` Alan Stern
2008-08-19 19:12 ` David Brownell
2008-08-19 20:04 ` Alan Stern
2008-08-19 21:05 ` juanslayton
2008-08-02 6:05 Aivils Stoss
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