[Bug 106223] [KBL-R] DP link training failures lead to downgraded link parameters and resolution

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https://bugs.freedesktop.org/show_bug.cgi?id=106223

--- Comment #45 from Sushma <sushma.venkatesh.reddy at intel.com> ---
I am able to reproduce the issue on WHL device - when two 4K external monitors
are connected, one 4K monitor is trained as 2K sometimes. I am connecting
monitors using (USB-C to DP) USB-C and (HDMI to HDMI) HDMI cables. Here are the
error messages that I am seeing:       
Line 2230: [  841.162692] [drm:intel_dp_start_link_train] Channel equalization
failed 5 times
Line 2231: [  841.162846] [drm:intel_dp_start_link_train] [CONNECTOR:90:DP-2]
Link Training failed at link rate = 540000, lane count = 4
I was able to reproduce the issue on drm tip but it is very hard to reproduce
like one out of 50 times.
I tried the patch that is specified in the above comments and couldn't
reproduce the bug. However, monitors take a longer time to train.
Attached the log in my previous comment for more details.

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