Created attachment 116643 [details]
dmesg_4840x2160.log

[    5.471830] i915 0000:00:02.0: Direct firmware load for i915/skl_dmc_ver1.bin failed with error -2
[    5.471980] [drm:i915_firmware_load_error_print [i915]] *ERROR* failed to load firmware i915/skl_dmc_ver1.bin (0)

Please ensure you have dmc firmware from [1] properly installed.

[1] https://01.org/linuxgraphics/downloads

Finding similar issue when loading the DUT with skl_dmc_ver1_18.bin. Attached the dmesg for your reference.

Vijay

Created attachment 116820 [details]
dmesg_dmc_loaded.log

(In reply to vijayakannan from comment #3)
> Finding similar issue when loading the DUT with skl_dmc_ver1_18.bin.
> Attached the dmesg for your reference.

Please reproduce using an upstream kernel, e.g. drm-intel-nightly branch of http://cgit.freedesktop.org/drm-intel

Please try to boot with i915.edp_vswing=1 or with i915.edp_vswing=2 as Kernel parameters. Do any of these solve your problem?

Bug scrub: looks like the same as #91269.
Let's Vijay answer to the question to confirm it.

Created attachment 117539 [details]
eDP_Resolution_3840x2160_xorg

i915.edp_vswing=1 or with i915.edp_vswing=2 is not solving this problem. Added the dmesg in the Related Jira bug. Adding Xorg.log in for your reference.

(In reply to cprigent from comment #7)
> Bug scrub: looks like the same as #91269.
> Let's Vijay answer to the question to confirm it.

Christophe, please reference other bugs like this: bug 91269 so they get linked automagically. Thanks.

Created attachment 117827 [details] [review]
ddi translation

Could you please check if this patch helps?

Hi Rodrigo,
Sorry for the delay. Issue is same with this patch. 

Thanks,
Vijay

Does this still occur?  Can you attach the dmesg as well from when the failure occurs?  See https://01.org/linuxgraphics/documentation/how-report-bugs

Can you test again with the latest drm-intel-nightly? I suspect this is due to cdclk being too low, but with the latest nightly we can now bump up the clock speed correctly. If it still fails, please attach full dmesg with the drm.debug=0xe option passed to the kernel.

The issue is not seen in SKL-Y platform with this configuration 

Software information 
============================================ 
Kernel version              	: 4.6.0-drm-intel-nightly-ww23-commit-fb023a2+ 
Linux distribution          	: Ubuntu 16.04 LTS 
Architecture                	: 64-bit 
Mesa version                	: 11.2.2 (git-3a9f628 
xf86-video-intel version    	: 2.99.917 
Xorg-Xserver version        	: 1.18.3 
DRM version                 	: 2.4.68 
VAAPI version               	: Intel i965 driver for Intel(R) Skylake - 1.7.0 
Cairo version               	: 1.15.2 
Intel GPU Tools version       	: Tag [intel-gpu-tools-1.14-348-g303b380] / Commit [303b380] 
Kernel driver in use        	: i915 
Hardware acceleration        	: Enabled 
Bios revision               	: 106.4 
KSC revision                	: 1.20 


 Hardware information 
============================================ 
Platform                     	: SKL-Y to KBL (RVP3) 
Motherboard model            	: Skylake Client platform 
Motherboard type             	: Skylake Y LPDDR3 RVP3 Laptop 
Motherboard manufacturer     	: Intel Corporation 
CPU family                   	: <OUT OF SPEC> 
CPU information              	: Intel(R) Core(TM) m5-6Y57 CPU @ 1.10GHz 
GPU Card                     	: Intel Corporation Sky Lake Integrated Graphics (rev 07) (prog-if 00 [VGA controller]) 
Memory ram                   	: 4 GB 
Maximum memory ram allowed   	: 16 GB 
CPU's number             	: 4 

 Firmwares information 
============================================ 
DMC fw loaded                	: yes 
DMC version                	: 1.26 


kernel configuration
=====================
commit fb023a2062df06c9e097e1f8f2bcf252194b9413
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Mon May 30 10:46:14 2016 +0200

    drm-intel-nightly: 2016y-05m-30d-08h-45m-53s UTC integration manifest


Kernel version : 4.6.0

eDP model
================
Samsung 4K eDP 1.3 panel 15.6" 3840x2160 non touch (SKL BOM#3) 

attachments
================
dmesg.log
xrandr.log

Created attachment 124287 [details]
xrandr.log

Created attachment 124288 [details]
dmesg.log

(In reply to maria guadalupe from comment #14)
> The issue is not seen in SKL-Y platform with this configuration 

Thanks, closing. Please reopen if the problem persists with latest kernels.

I can't double confirm as my SKL as no eDP.
Closed. Please re-open if needed.