Bug 78309

Summary: Plugging 12+ USB devices, error in src/evdev.c: no such file
Product: xorg Reporter: proyectomultik
Component: Input/evdevAssignee: Peter Hutterer <peter.hutterer>
Status: RESOLVED FIXED QA Contact: Xorg Project Team <xorg-team>
Severity: normal    
Priority: medium CC: peter.hutterer, proyectomultik
Version: 7.7 (2012.06)   
Hardware: x86-64 (AMD64)   
OS: Linux (All)   
Whiteboard:
i915 platform: i915 features:
Attachments:
Description Flags
GDB X.org Backtrace
none
Xorg.log none

Description proyectomultik 2014-05-05 19:23:32 UTC 
Created attachment 98513 [details]
GDB X.org Backtrace

When plugging 12 USB keyboards + 4 USB hubs in desktop computer, X.org crashes and closes. I can access the terminal, but trying to restart X throws an error. 

As seen in the backtrace, the problem is in EvdevIsDuplicate (evdev.c), when trying to open a new device.

I am using Ubuntu 12.04 and kernel 3.11.0-20-generic. When using kernel 3.6 and plugging the same devices, there is no crash.

I think this may be related to dynamic minor allocation in evdev, which was pushed to linux kernel in version 3.7:

https://groups.google.com/forum/#!topic/linux.kernel/TymfXEsu7GA 
https://groups.google.com/forum/#!topic/linux.kernel/WgBgg-dHB1s

Why do I need to plug that many keyboards? It is a multiseat project, currently being tested in chilean elementary schools :)
Comment 1 proyectomultik 2014-05-05 19:24:33 UTC 
Created attachment 98514 [details]
Xorg.log
Comment 2 Peter Hutterer 2014-05-06 00:43:11 UTC 
http://patchwork.freedesktop.org/patch/25452/
Comment 3 Peter Hutterer 2014-05-07 23:24:31 UTC 
commit 13dea90bc8ef2a2e6f55fb5ff5f54afe41d22f95
Author: Peter Hutterer <peter.hutterer@who-t.net>
Date:   Tue May 6 09:20:05 2014 +1000

    Use the server's device list for duplicate detection (#78309)
Comment 4 proyectomultik 2014-05-14 21:25:39 UTC 
Tested with 24 keyboards and it's working. Thank you.

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