Resending as plain-text :-(

Also on bugzilla.kernel.org: https://bugzilla.kernel.org/show_bug.cgi?id=196297

Setup and brief environment: - Kernel 4.12.0 - vanilla, no patches - Dual-monitor setup - Monitor 1: - Dell U3011 30-inch 2560x1600 over DVI-I - Never has a problem - Monitor 2: - Seiki SE39UY04 (TV) over DisplayPort @3840x2160 - Has a problem ONLY when monitor is SWITCHED OFF AND ON AGAIN - Graphics card: - GeForce GTX 750Ti 2GB GDDR5 128bit, Dual-Link DVI-I, HDMI, DP 1.2 Graphics Card - eVGA 02G-P4-3753-KR - eVGA link: http://www.evga.com/Products/Product.aspx?pn=02G-P4-3753-KR - Seiki monitor EDID: - The monitor has a bad EDID - see attached orig_edid.bin - I have a modified EDID file - see attached edid2.bin with ONLY the correct resolution - I use video=DP-1:3840x2160 drm_kms_helper.edid_firmware=DP-1:edid/edid2.bin to specify the exact resolution and use my custom EDID file

What works (perfectly): - Both monitors startup at full resolution - xorg starts up at full resolution on both monitors - Monitor 1 (Dell U3011) NEVER has any problem - While booting, nouveau finds and uses my custom EDID file

Problem: - When DPMS kicks in, the Dell U3011 monitor goes to sleep (normal) and the Seiki monitor shows 'No Signal' on the screen - About 15 mins after DPMS kicks in, the Seiki monitor switches off - The Seiki monitor has to be manually switched on with the power button - This behavior cannot be changed - no setting for this on the monitor - When I switch the Seiki monitor ON, the screen will be blank and 'xrandr -q' shows it as disconnected - When I switch to a virtual console (using CTRL-ALT-F1), the following message appears on the console:

Jul 7 23:34:28 smaug kernel: [ 8340.750889] nouveau 0000:03:00.0: disp: outp 03:0006:0f42: link training failed Jul 7 23:34:28 smaug kernel: [ 8340.750940] nouveau 0000:03:00.0: disp: outp 03:0006:0f42: link not trained before attach

- This message appears ONLY when I switch to the virtual console, and NOT until then - When the monitor is switched on, the attached kernel trace appears in the kernel log - After switching to the virtual console and back to X, the monitor will show a SERIES of garbled screens (probably bad timings, but I am not sure), each lasting about 10-15 secs. After a few MINUTES (perhaps 2-3 minutes), the Seiki monitor will be restored back to full resolution - As the monitor is restored to full resolution, the following message will appear in the kernel log:

Jul 7 23:37:44 smaug kernel: [ 8537.487664] [drm] Got external EDID base block and 1 extension from "edid/edid2.bin" for connector "DP-1"

- The problem only happens if the Seiki monitor is in the OFF state for QUITE A LONG TIME - E.g., if I turn it back on within 5 mins, the problem does not occur

Problem wasn't happening until about 4-5 months ago (when I was using an older kernel version). I have gone back to 4.11, but it still happens. Must be a versionolder than that. Unfortunately, I do not remember which version worked, but was a 4.x version.