Arch Linux

costis

Member

Registered: 2014-10-02

Posts: 14

[SOLVED] Kernel Mode Setting does not seem to work

Today I switched from ubuntu to Arch!

I have configured kdm by editing

/usr/share/config/kdm/kdmrc

to automatically open two displays:

StaticServers=:0,:1

This way I can have two different users logged-in at the same time with different desktops, applications, etc...
When I switch between them with Ctrl+Alt+F7-8 there is a delay of about 2 seconds which is extremely annoying. The same happens when I

startx

directly from a tty without the intervention of kdm. If I change Window Manager (like openbox or twm) the problem remains.

How could I make this switch as instantaneous as possible?

EDIT:
It seems it is a KMS related issue, but after following https://wiki.archlinux.org/index.php/Ke … de_setting and https://wiki.archlinux.org/index.php/Intel_graphics instantaneous user-switching does not seem to work. I know it is not a hardware-related issue, because it works in ubuntu.

Thanks!

$ grep -e driver /var/log/Xorg.0.log 
[     4.624]    X.Org XInput driver : 21.0
[     4.627] (==) Matched intel as autoconfigured driver 0
[     4.627] (==) Matched modesetting as autoconfigured driver 1
[     4.627] (==) Matched fbdev as autoconfigured driver 2
[     4.627] (==) Matched vesa as autoconfigured driver 3
[     4.627] (==) Assigned the driver to the xf86ConfigLayout
[     4.627] (II) Loading /usr/lib/xorg/modules/drivers/intel_drv.so
[     4.962] (II) intel(0): Using Kernel Mode Setting driver: i915, version 1.6.0 20080730
[     4.964] (II) intel(0): [DRI2]   DRI driver: i965
[     4.964] (II) intel(0): [DRI2]   VDPAU driver: i965
[     5.032]    ABI class: X.Org XInput driver, version 21.0
[     5.032] (II) Using input driver 'evdev' for 'Power Button'
[     5.053] (II) Using input driver 'evdev' for 'Video Bus'
[     5.053] (II) Using input driver 'evdev' for 'Power Button'
[     5.054] (II) Using input driver 'evdev' for 'Forward USB Optical Mouse'
[     5.055] (II) No input driver specified, ignoring this device.
[     5.055] (II) Using input driver 'evdev' for 'Microsoft Comfort Mouse 6000'
[     5.056] (II) No input driver specified, ignoring this device.
[     5.056] (II) Using input driver 'evdev' for 'Microsoft Natural® Ergonomic Keyboard 4000'
[     5.057] (II) Using input driver 'evdev' for 'Microsoft Natural® Ergonomic Keyboard 4000'
[     5.057] (II) No input driver specified, ignoring this device.

$ dmesg | grep drm
[    2.696528] [drm] Initialized drm 1.1.0 20060810
[    2.793949] [drm] Memory usable by graphics device = 2048M
2.793951] [drm] Replacing VGA console driver
2.793955] fb: switching to inteldrmfb from VESA VGA
2.813970] [drm] Supports vblank timestamp caching Rev 2 (21.10.2013).
2.813971] [drm] Driver supports precise vblank timestamp query.
[    2.890589] [drm] GMBUS [i915 gmbus dpc] timed out, falling back to bit banging on pin 4
[    2.991700] fbcon: inteldrmfb (fb0) is primary device
[    3.027016] [drm:cpt_set_fifo_underrun_reporting] *ERROR* uncleared pch fifo underrun on pch transcoder A
[    3.027017] [drm:cpt_serr_int_handler] *ERROR* PCH transcoder A FIFO underrun
[    3.033464] i915 0000:00:02.0: fb0: inteldrmfb frame buffer device
[    3.062197] [drm] Initialized i915 1.6.0 20080730 for 0000:00:02.0 on minor 0
[    4.314306] [drm] Enabling RC6 states: RC6 on, RC6p on, RC6pp off

Last edited by costis (2015-02-28 17:13:39)

ewaller

Administrator

From: Pasadena, CA

Registered: 2009-07-13

Posts: 20,722

Re: [SOLVED] Kernel Mode Setting does not seem to work

Did you set your host name correctly?  From a console, what is the output of hostname   ?

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costis

Member

Registered: 2014-10-02

Posts: 14

Re: [SOLVED] Kernel Mode Setting does not seem to work

I suppose I did. What I have done is:

$ echo myhostname > /etc/hostname
$ cat /etc/hostname 
myhostname

  and I aldo added it in the 127.0.0.1 line of /etc/hosts, so now it's

$ cat /etc/hosts
#
# /etc/hosts: static lookup table for host names
#

#<ip-address>   <hostname.domain.org>   <hostname>
127.0.0.1       localhost.localdomain   localhost       myhostname
::1             localhost.localdomain   localhost

# End of file

I have verified this with two ways:

$ uname -a
Linux myhostname 3.16.4-1-ARCH #1 SMP PREEMPT Mon Oct 6 08:22:27 CEST 2014 x86_64 GNU/Linux
$ ping myhostname
PING localhost.localdomain (127.0.0.1) 56(84) bytes of data.
64 bytes from localhost.localdomain (127.0.0.1): icmp_seq=1 ttl=64 time=0.025 ms

costis

Member

Registered: 2014-10-02

Posts: 14

Re: [SOLVED] Kernel Mode Setting does not seem to work

I tried the live CDs of Fedora, ArchBang, Antergos, ChakraOS. Fedora and ChakraOS does not have this "problem". So I now run ChakraOS,... and my problem seems  "lamely" solved. I will ask there if they have any idea of why this happened. Thanks.

Edit: I do not know how and why, but after some kernel versions the problem does not appear any more and KMS works fine.

Last edited by costis (2015-02-28 17:13:24)