From: Aivils Stoss <aivils@latnet.lv>
To: linux-input@vger.kernel.org, jkosina@suse.cz,
linux-kernel@vger.kernel.org,
linuxconsole-dev@lists.sourceforge.net
Subject: PROBLEM: USB keyboards works only 4 per PC host port
Date: Fri, 8 Aug 2008 07:02:24 +0100 [thread overview]
Message-ID: <200808080702.24969.aivils@latnet.lv> (raw)
Hello All!
PROBLEM: USB keyboards works only 4 per PC host port.
I work for project which will use 15 - 25 keyboards for children teaching.
I discover current Linux 2.6.22 , 2.6.24, 2.6.26 dot not support more
than 4 keyboards per single PC host port. All plugged in keyboards
are listed as USB devices, listed as input devices, but capable to
send input events are only 4 keyboards, no matter where keyboards
are plugged in to HUB cascade. All plugged in keyboards switch LED's,
when i press NumLock.
I tested various usb-hub units and various host PC hardware, i even
replace hub power supplay units from 5V1A to 5V3A. All tested cases
give best results - 4 keyboards per PC host port and worstest - some PC
cannot do more than 8 keyboards at all.
I suppose this is Linux kernel bug because i test keyboards under
Windows, which support any schema of cascading of usb hubs.
I will send any log file if that is necessary, but trouble will pop up
in a row of kernels. 2.6.22 didn't have error messages. 2.6.24, 2.6.26
tend to total slow down with eternal reset messages:
Jul 25 07:16:00 awork kernel: input,hiddev97: USB HID v1.10 Mouse
[USB-compliant keyboard] on usb-0000:00:1d.0-1.1.2
Jul 25 07:16:01 awork kernel: usb 2-1.1.1: reset low speed USB device using
uhci_hcd and address 17
Jul 25 07:16:01 awork kernel: usb 2-1.1.2: reset low speed USB device using
uhci_hcd and address 18
Jul 25 07:16:02 awork kernel: usb 2-1.1.1: reset low speed USB device using
uhci_hcd and address 17
Best regards,
Aivils Stoss
next reply other threads:[~2008-08-09 6:29 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-08-08 6:02 Aivils Stoss [this message]
2008-08-09 10:42 ` PROBLEM: USB keyboards works only 4 per PC host port 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
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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