Subject: bug#24789: Changing console renders my system unresponsive

From: Petter <[email-masked]>
Date: Tue, 25 Oct 2016 13:22:53 +0200

Hi,

I'm having a pretty dramatic experience changing console, f.ex. 
Ctrl+Alt+F4. My system becomes completely unresponsive. Even 
Alt+SysRq+reisub is unable to persuade my system to perform a gentlemans 
reboot. To recover I must do a hard reboot.

Bringing this up in #guix suggests it's not a common issue.

My setup is:
Libreboot X200
Docking station
External monitor connected to the docking station with DisplayPort.
XFCE
GuixSD (from git, last commit in my repo 
c11933c920dd7b7cdf68e13e6b3718602129210a)

Using DisplayPort I sometimes get the attached output. Other times I get 
a white underscore in the top left corner on a black background.

Now, if I change video output to Laptop monitor and unplug the 
DisplayPort cable I can change consoles. (Only setting video output to 
Laptop is not enough, the cable must go.)

If I use VGA instead, changing consoles seems to work fine. However 
running command "dmesg" tells of a Call Trace that looks much like the 
Call Trace I sometimes see when my system becomes unresponsive 
(attached), though a bit shorter.

---This is dmesg after changing consoles with VGA:---
[18562.847011] WARNING: CPU: 0 PID: 358 at 
drivers/gpu/drm/i915/intel_display.c:13094 intel_atomic_c
ommit_tail+0xec9/0x11b0 [i915]
[18562.847013] pipe state doesn't match!
[18562.847014] Modules linked in: appletalk ax25 ipx p8023 p8022 psnap 
llc iTCO_wdt iTCO_vendor_supp
ort snd_hda_codec_conexant snd_hda_codec_generic arc4 coretemp kvm_intel 
kvm irqbypass ath9k i915 ps
mouse drm_kms_helper ath9k_common serio_raw ath9k_hw ath mac80211 
i2c_i801 uvcvideo drm i2c_smbus sn
d_hda_intel videobuf2_vmalloc videobuf2_memops snd_hda_codec 
videobuf2_v4l2 joydev lpc_ich thinkpad_
acpi snd_hda_core i2c_algo_bit fb_sys_fops syscopyarea videobuf2_core 
sysfillrect input_leds snd_hwd
ep cfg80211 sysimgblt videodev snd_pcm usbkbd media nvram usbmouse 
snd_timer e1000e snd soundcore pt
p shpchp fjes video pps_core mac_hid virtio_console virtio_net 
virtio_blk virtio_balloon virtio_pci
virtio virtio_ring isci libsas scsi_transport_sas pata_atiixp pata_acpi 
nvme nvme_core wp512 serpent
_generic xts
[18562.847065]  gf128mul dm_crypt hid_apple hid_generic usbhid hid uas 
usb_storage ahci libahci [las
t unloaded: pcspkr]
[18562.847076] CPU: 0 PID: 358 Comm: X Tainted: G        W I     
4.8.2-gnu #1
[18562.847078] Hardware name: LENOVO 7458WLD/7458WLD, BIOS CBET4000 4.0 
05/18/2015
[18562.847080]  0000000000000286 000000003943eb96 ffff995f6d297a70 
ffffffffa53ede43
[18562.847084]  ffff995f6d297ac0 0000000000000000 ffff995f6d297ab0 
ffffffffa50831e1
[18562.847087]  00003326c089ec22 ffff995f6cd11800 ffff995f6d0d4000 
ffff995f6cd10800
[18562.847090] Call Trace:
[18562.847097]  [<ffffffffa53ede43>] dump_stack+0x63/0x90
[18562.847101]  [<ffffffffa50831e1>] __warn+0xd1/0xf0
[18562.847103]  [<ffffffffa508325f>] warn_slowpath_fmt+0x5f/0x80
[18562.847130]  [<ffffffffc08ab7d9>] 
intel_atomic_commit_tail+0xec9/0x11b0 [i915]
[18562.847133]  [<ffffffffa50c7840>] ? wait_woken+0x80/0x80
[18562.847159]  [<ffffffffc08abec7>] intel_atomic_commit+0x407/0x570 
[i915]
[18562.847191]  [<ffffffffc060f161>] ? drm_atomic_check_only+0x141/0x640 
[drm]
[18562.847206]  [<ffffffffc060fcf7>] ? 
drm_atomic_set_crtc_for_connector+0x97/0x100 [drm]
[18562.847221]  [<ffffffffc060f697>] drm_atomic_commit+0x37/0x60 [drm]
[18562.847234]  [<ffffffffc07fbc22>] 
drm_atomic_helper_set_config+0x82/0xc0 [drm_kms_helper]
[18562.847248]  [<ffffffffc05fdfc5>] 
drm_mode_set_config_internal+0x65/0x110 [drm]
[18562.847262]  [<ffffffffc060279c>] drm_mode_setcrtc+0x1ec/0x580 [drm]
[18562.847274]  [<ffffffffc05f5132>] drm_ioctl+0x202/0x510 [drm]
[18562.847288]  [<ffffffffc06025b0>] ? drm_mode_setplane+0x1c0/0x1c0 
[drm]
[18562.847292]  [<ffffffffa522bb27>] ? __vfs_read+0x37/0x150
[18562.847295]  [<ffffffffa5240cef>] do_vfs_ioctl+0x9f/0x5e0
[18562.847299]  [<ffffffffa5091211>] ? __set_task_blocked+0x41/0xa0
[18562.847301]  [<ffffffffa5093b66>] ? __set_current_blocked+0x36/0x60
[18562.847304]  [<ffffffffa52412a9>] SyS_ioctl+0x79/0x90
[18562.847307]  [<ffffffffa5847d36>] entry_SYSCALL_64_fastpath+0x1e/0xa8
[18562.847309] ---[ end trace f68728a0d3053b57 ]---

I have no idea if this is really a Guix issue or not, maybe it's 
Linux-libre?

Let me know if I can be of any assistance.

--
Petter
#guix Petter