PROBLEM: USB keyboards works only 4 per PC host port

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



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
--
To unsubscribe from this list: send the line "unsubscribe linux-input" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html

[Index of Archives]     [Linux Media Devel]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [Linux Wireless Networking]     [Linux Omap]

  Powered by Linux