Created attachment 122085 [details]
dmesg from cold boot with two monitors connected

distro: Fedora 23 (up to date)
kernel: 4.4.2-301.fc23.x86_64
xorg-x11-drv-nouveau-1.0.12-3.fc23.x86_64
xorg-x11-server-Xorg-1.18.0-2.fc23.x86_64

The full dmesg is attached showing the panics from a cold boot when two monitors are connected. One on DVI the other on HDMI.

First is:

[   18.097956] ------------[ cut here ]------------
[   18.097963] WARNING: CPU: 0 PID: 498 at include/drm/drm_crtc.h:1565 drm_helper_choose_encoder_dpms+0x8a/0x90 [drm_kms_helper]()
[   18.097964] Modules linked in: ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 xt_conntrack ip_set nfnetlink ebtable_nat ebtable_filter ebtable_broute bridge ebtables ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_raw ip6table_security ip6table_filter ip6_tables iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_raw iptable_security joydev xpad ff_memless vfat fat nouveau i2c_algo_bit ttm intel_rapl snd_hda_codec_realtek iosf_mbi x86_pkg_temp_thermal iTCO_wdt drm_kms_helper snd_hda_codec_hdmi iTCO_vendor_support drm eeepc_wmi asus_wmi coretemp sparse_keymap snd_hda_codec_generic rfkill kvm_intel snd_hda_intel snd_hda_codec kvm shpchp i2c_i801 irqbypass crct10dif_pclmul crc32_pclmul crc32c_intel snd_hda_core snd_hwdep snd_seq
[   18.097984]  snd_seq_device tpm_infineon mei_me lpc_ich snd_pcm snd_timer snd soundcore tpm_tis tpm mei acpi_pad nfsd auth_rpcgss nfs_acl lockd grace sunrpc raid1 mxm_wmi 8021q garp stp llc mrp r8169 serio_raw mii wmi fjes video
[   18.097995] CPU: 0 PID: 498 Comm: kworker/0:2 Not tainted 4.4.2-301.fc23.x86_64 #1
[   18.097996] Hardware name: ASUS All Series/Z97-P, BIOS 2803 05/21/2015
[   18.098009] Workqueue: events nvif_notify_work [nouveau]
[   18.098010]  0000000000000000 0000000014d050dd ffff880407e43d10 ffffffff813b0c9f
[   18.098011]  0000000000000000 ffff880407e43d48 ffffffff810a2f12 ffff88040875a800
[   18.098012]  ffff880408d9a200 ffff880409d09000 0000000000000003 ffff880408f5e3e8
[   18.098013] Call Trace:
[   18.098017]  [<ffffffff813b0c9f>] dump_stack+0x44/0x55
[   18.098019]  [<ffffffff810a2f12>] warn_slowpath_common+0x82/0xc0
[   18.098021]  [<ffffffff810a305a>] warn_slowpath_null+0x1a/0x20
[   18.098022]  [<ffffffffa03c52ca>] drm_helper_choose_encoder_dpms+0x8a/0x90 [drm_kms_helper]
[   18.098024]  [<ffffffffa03c53bb>] drm_helper_connector_dpms+0x4b/0x100 [drm_kms_helper]
[   18.098039]  [<ffffffffa04b973b>] nouveau_connector_hotplug+0x3b/0xb0 [nouveau]
[   18.098044]  [<ffffffffa0419a77>] nvif_notify_work+0x27/0xa0 [nouveau]
[   18.098045]  [<ffffffff817993de>] ? _raw_spin_unlock_irqrestore+0xe/0x10
[   18.098047]  [<ffffffff810baa4d>] ? pwq_dec_nr_in_flight+0x4d/0xa0
[   18.098048]  [<ffffffff810bb10e>] process_one_work+0x19e/0x3f0
[   18.098050]  [<ffffffff810bb3ae>] worker_thread+0x4e/0x450
[   18.098051]  [<ffffffff81795290>] ? __schedule+0x3e0/0x9b0
[   18.098052]  [<ffffffff810bb360>] ? process_one_work+0x3f0/0x3f0
[   18.098053]  [<ffffffff810bb360>] ? process_one_work+0x3f0/0x3f0
[   18.098055]  [<ffffffff810c1138>] kthread+0xd8/0xf0
[   18.098056]  [<ffffffff810c1060>] ? kthread_worker_fn+0x160/0x160
[   18.098057]  [<ffffffff81799ccf>] ret_from_fork+0x3f/0x70
[   18.098058]  [<ffffffff810c1060>] ? kthread_worker_fn+0x160/0x160
[   18.098059] ---[ end trace bd2c6dc17e96933e ]---