Next step would be to try with the firmware made for Kabylake platform.
But the patch to enable it does not apply with fresh kernel.

Created attachment 123279 [details] [review]
kbl 1.01 loading patch

I confirm it is not reproduced with DMC kbl 1.01 (so with the patch applied).

Created attachment 123285 [details] [review]
v3

Please re-test with this new version.

Probably the previous one was not allowing DC states at all.

Thanks,
Rodrigo.

the detected bug was crashing again in the last run with the next parameters

Hardware configuration
=======================
Platform     KBL


Kernel information
===============================================
commit bcc6a843e7e4a3f4794b90dbefb00174171365bd
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Mon May 9 13:48:17 2016 +0100

    drm-intel-nightly: 2016y-05m-09d-12h-47m-46s UTC integration manifest


Kernel version : 4.6.0-rc7
Architecture : source amd64 all
Homepage : http://www.kernel.org/


dmc Version: 1.01

(In reply to maria guadalupe from comment #5)
> the detected bug was crashing again in the last run with the next parameters

How does it crash? Could you provide the logs?

(In reply to Imre Deak from comment #6)
> (In reply to maria guadalupe from comment #5)
> > the detected bug was crashing again in the last run with the next parameters
> 
> How does it crash? Could you provide the logs?

Hi Deak :

Sorry for my last comment, that i was trying to said is that i saw the issue reporting here, i mean 


[   93.657098] [drm:gen9_set_dc_state [i915]] *ERROR* DC state mismatch (0x0 -> 0x2)

Created attachment 123626 [details]
kbl-dmesg-igt-all

Patch v3 is already available with last kernel from nightly

While launching IGT all, I see this error several times:
root@KBLU1:~# grep -i "DC state mismatch" /var/log/kern.log
May 11 11:42:13 KBLU1 kernel: [   44.501739] [drm:gen9_set_dc_state [i915]] *ERROR* DC state mismatch (0x0 -> 0x2)
May 11 11:52:37 KBLU1 kernel: [  597.702751] [drm:gen9_set_dc_state [i915]] *ERROR* DC state mismatch (0x0 -> 0x2)
May 11 12:24:05 KBLU1 kernel: [  254.040659] [drm:gen9_set_dc_state [i915]] *ERROR* DC state mismatch (0x0 -> 0x2)
May 11 14:19:44 KBLU1 kernel: [  385.919901] [drm:gen9_set_dc_state [i915]] *ERROR* DC state mismatch (0x0 -> 0x2)
May 11 16:16:15 KBLU1 kernel: [   26.853465] [drm:gen9_set_dc_state [i915]] *ERROR* DC state mismatch (0x0 -> 0x2)
May 11 17:34:49 KBLU1 kernel: [    7.389852] [drm:gen9_set_dc_state [i915]] *ERROR* DC state mismatch (0x0 -> 0x2)

The right firmware is loaded:
root@KBLU1:~# dmesg |grep dmc
May 11 17:41:43 KBLU1 kernel: [    1.788870] [drm:intel_csr_ucode_init] Loading i915/kbl_dmc_ver1.bin
May 11 17:41:43 KBLU1 kernel: [    1.789281] [drm] Finished loading i915/kbl_dmc_ver1.bin (v1.1)

root@KBLU1:~# cat /sys/kernel/debug/dri/0/i915_dmc_info
fw loaded: yes
path: i915/kbl_dmc_ver1.bin
version: 1.1
program base: 0x09004040
ssp base: 0x00002fc0
htp: 0x00b40068

Tested with same platform
Kernel: drm-intel-nightly 4.6.0-rc7 61f856f from http://cgit.freedesktop.org/drm-intel/
  commit 61f856faa1e6ff9dddad214be1e372e8aacfc0f4
  Author: Ville Syrjälä <ville.syrjala@linux.intel.com>
  Date:   Mon May 9 19:24:21 2016 +0300
  drm-intel-nightly: 2016y-05m-09d-16h-24m-01s UTC integration manifest
drm: libdrm 2.4.68 ea78c17 from git://anongit.freedesktop.org/mesa/drm
cairo: 1.15.2 db8a7f1 from git://anongit.freedesktop.org/cairo
IGT: 1.14 cc24755 from http://anongit.freedesktop.org/git/xorg/app/intel-gpu-tools.git

(In reply to cprigent from comment #8)
> Created attachment 123626 [details]
> kbl-dmesg-igt-all
> 
> Patch v3 is already available with last kernel from nightly
> 
> While launching IGT all, I see this error several times:
> root@KBLU1:~# grep -i "DC state mismatch" /var/log/kern.log

Could you attach the dmesg log that starts from bootup containing more of these error messages?

  (In reply to Imre Deak from comment #9)
> (In reply to cprigent from comment #8)
> > Created attachment 123626 [details]
> > kbl-dmesg-igt-all
> > 
> > Patch v3 is already available with last kernel from nightly
> > 
> > While launching IGT all, I see this error several times:
> > root@KBLU1:~# grep -i "DC state mismatch" /var/log/kern.log
> 
> Could you attach the dmesg log that starts from bootup containing more of
> these error messages?

Hi Deak :

Please see the kern.log where it has the following parameters :
log_buf_len=4m / drm.debug=14

Created attachment 123835 [details]
kern

(In reply to maria guadalupe from comment #11)
> Created attachment 123835 [details]
> kern

This doesn't have any DC mismatch errors or any other error. Please attach a similar log starting from bootup by reproducing the bug.

(In reply to Imre Deak from comment #12)
> (In reply to maria guadalupe from comment #11)
> > Created attachment 123835 [details]
> > kern
> 
> This doesn't have any DC mismatch errors or any other error. Please attach a
> similar log starting from bootup by reproducing the bug.

Sorry my bad, attached the correct one for KBL

attachment
===========
dmesg.log

Created attachment 123838 [details]
dmesg.log

Created attachment 127541 [details]
KBL__4.9-rc2__DC_state_mismatch_when_suspending_to_disk__kern.log

Still reproduced

root@KBLU3:/home/user# rtcwake -m disk -s 60
rtcwake: assuming RTC uses UTC ...
rtcwake: wakeup from "disk" using /dev/rtc0 at Tue Oct 25 12:50:42 2016
root@KBLU3:/home/user#
root@KBLU3:/home/user#
root@KBLU3:/home/user# dmesg |grep "DC state"
[ 1274.659209] [drm:gen9_set_dc_state [i915]] Setting DC state from 00 to 02
[ 1274.659640] [drm:gen9_set_dc_state [i915]] Setting DC state from 02 to 00
[ 1274.893412] [drm:gen9_set_dc_state [i915]] Setting DC state from 02 to 00
[ 1274.893425] [drm:gen9_set_dc_state [i915]] *ERROR* DC state mismatch (0x0 -> 0x2)
[ 1274.896299] [drm:gen9_set_dc_state [i915]] Setting DC state from 00 to 00
[ 1274.896398] [drm:gen9_set_dc_state [i915]] Setting DC state from 00 to 00

Platform: KABY LAKE-U
Processor : Genuine Intel(R) CPU 0000 @ 1.80GHz (cpu family: 6, model: 142, stepping: 9)
MCP : KBL-U J0 2+3e
QDF : QL9J
PCH: PCH-LP C1
CRB : KABY LAKE U DDR3L RVP7
Rework: O-16

Software
BIOS: 45.1 3KBLSE2R1.R00.X045.P01.1606291634 from https://ubit-artifactory-ba.intel.com/artifactory/owr-repos/Submissions/ifwi/KBL_ORANGE_IFWI_2016_WW27_3_03_SR'17/
ME FW: 11.6.0.1065
EC FW: 1.24
KSC: 1.24
Linux distribution: Ubuntu 16.04 64 bits
DMC 1.01 from https://01.org/sites/default/files/downloads/intelr-graphics-linux/kbldmcver101.tar.bz2
GuC 9.14 from http://rdvivi-hillsboro.jf.intel.com/firmware/kbl_guc_ver9_14.tar.bz2 
Kernel: 4.9.0-rc2 194359e from http://cgit.freedesktop.org/drm-intel/
  commit 194359e4a31ff988c7a290093820c5ef28d3752b
  Author: Paulo Zanoni <paulo.r.zanoni@intel.com>
  Date:   Mon Oct 24 17:44:02 2016 -0200
  drm-intel-nightly: 2016y-10m-24d-19h-42m-14s UTC integration manifest
libdrm-2.4.71 9e24d0c from git://anongit.freedesktop.org/mesa/drm
mesa: mesa-12.0.0 8b06176 from git://anongit.freedesktop.org/mesa/mesa
cairo 1.15.2 db8a7f1 from git://anongit.freedesktop.org/cairo
xorg-server-1.18.99.901-80 5dcb066 from git://git.freedesktop.org/git/xorg/xserver
xf86-video-intel 2.99.917-720 388fd4a from git://git.freedesktop.org/git/xorg/driver/xf86-video-intel
libva-1.7.2-38 3b7e499 from git://git.freedesktop.org/git/vaapi/libva 
vaapi-intel-driver: 1.7.2-140 852cea1 from git://git.freedesktop.org/git/vaapi/intel-driver
IGT: intel-gpu-tools-1.16-96 93437cb from http://anongit.freedesktop.org/git/xorg/app/intel-gpu-tools.git

External screen: ASUS PB238Q (DP)

I get this message only after suspend to disk (hibernation) on my Skylake Core m 6Y30, with Linux 4.8.8.

Created attachment 128002 [details]
dmesg from a Skylake Core m 6Y30

Forgot my dmesg which shows the mismatch after coming back from hibernation on my Core m 6Y30

% lspci -n -s 0:2                    
00:02.0 0300: 8086:191e (rev 07)

% dmesg | grep "Finished loading"   
[    0.996314] [drm] Finished loading i915/skl_dmc_ver1_26.bin (v1.26)

Ricardo and Thomas, is the problem still valid for the latest kernels (preferable drm-tip from git://anongit.freedesktop.org/git/drm-tip)? If yes then please mark status REOPENED, and attach the latest logs/info (see https://01.org/linuxgraphics/documentation/how-report-bugs)

Created attachment 131454 [details]
kernel log

This issues is not reproduce with the following configuration on KBL:

======================================
             Software
======================================
kernel version              : 4.12.0-rc2-drm-tip-ww21-commit-c6d01be+
architecture                : x86_64
os version                  : Ubuntu 16.10
os codename                 : yakkety
kernel driver               : i915
bios revision               : 5.6
bios release date           : 05/03/2017
ksc                         : 8.1

======================================
        Graphic drivers
======================================
modesetting                 : modesetting_drv.so
xorg-xserver                : 1.18.4
libdrm                      : 2.4.80
cairo                       : 1.15.5
xserver                     : X.Org X Server 1.18.4
intel-gpu-tools (tag)       : intel-gpu-tools-1.18-194-g9ba644d
intel-gpu-tools (commit)    : 9ba644d

======================================
             Hardware
======================================
motherboard id             : NUC7i5BNB
form factor                : Desktop
cpu family                 : Core i5
cpu family id              : 6
cpu information            : Intel(R) Core(TM) i5-7260U CPU @ 2.20GHz
gpu card                   : Intel Corporation Device 5926 (rev 06) (prog-if 00 [VGA controller])
memory ram                 : 15.58 GB
max memory ram             : 32 GB
cpu thread                 : 4
cpu core                   : 2
cpu model                  : 142
cpu stepping               : 9
signature                  : Type 0, Family 6, Model 142, Stepping 9
hard drive                 : 447GiB (480GB)
current cd clock frequency : 337500 kHz
maximum cd clock frequency : 675000 kHz
displays connected         : DP-1 DP-2

======================================
             Firmware
======================================
dmc fw loaded             : yes
dmc version               : 1.1
guc fw loaded             : NONE
guc version wanted        : 0.0
guc version found         : 0.0

======================================
             kernel parameters
======================================
quiet drm.debug=0xe auto panic=1 nmi_watchdog=panic resume=/dev/sda3 fastboot

I attached dmc_kern.log and dmesg.log.

Created attachment 131455 [details]
dmesg log

I can still reproduce this during suspend/hibernate tests on SKL Skull Canyon NUC (NUC6i7KYK), so the same DMC firmware update probably needs to be rolled to SKL too.

Created attachment 133376 [details] [review]
Patch to fix DC mismatch during hibernation/resume

(In reply to Joonas Lahtinen from comment #22)
> I can still reproduce this during suspend/hibernate tests on SKL Skull
> Canyon NUC (NUC6i7KYK), so the same DMC firmware update probably needs to be
> rolled to SKL too.

Joonas, could you try the attached fix?

Hello Joonas, any update with Imre's patch? Thank you.

(In reply to Elizabeth from comment #24)
> Hello Joonas, any update with Imre's patch? Thank you.

The fix has been merged to drm-tip, so marking it FIXED.