Steps to reproduce the problem:

* have a kernel (~> 4.6 ) where drm is able to do deep color
* have an chip that uses i915 
* have a deep color able TV screen (1080p)
* connect them via a CAT5-bridge (as in our meeting rooms be done) that can handle 1060p only on 8bit.

Happens all the time.

This setup breaks with and only with Linux laptops with recent kernels, due to them turning on deep color which seemingly overloads the CAT5 bridge and thus the screen starts flickering (turning to black every 10-20 seconds for half a second).

Following "patch" solves the issue for me, since it forcefully disables all deep color ability for this notebook:

----
linux-4.11.2$ diff -u drivers/gpu/drm/drm_edid.c.org drivers/gpu/drm/drm_edid.c
--- drivers/gpu/drm/drm_edid.c.org    2017-05-24 14:08:19.162452768 +0200
+++ drivers/gpu/drm/drm_edid.c    2017-05-24 14:10:33.149417356 +0200
@@ -3803,6 +3803,7 @@
 
     if (cea_db_payload_len(hdmi) < 6)
         return;
+    return;
 
     if (hdmi[6] & DRM_EDID_HDMI_DC_30) {
         dc_bpc = 10;
------

I'd wish there was a module parameter to force this off, other than hacking the source. (Or I kept overlooking an existing one)

PS: As far I realize, unless this is a more sophisticated EDID bug, at fault here is that stupid CAT5-bridge that is supposed to modify the EDID to something it can handle, which it doesn't.