Intel HD 620 Linux HDMI - No Signal

[spease]

Hi,

I have a Lenovo X1 Yoga 2nd generation, with the Intel HD 620 chipset, running Arch Linux, up-to-date with the latest kernel from the Arch repo. It has a built-in HDMI port I'd like to use.

Using the i915 driver, I can see a connected HDMI 4k tv in xrandr. However, the TV invariably reports 'no signal' regardless of the TV (I have tried three of differing models). I have tried telling xrandr to set different resolutions, and changing a few properties, but nothing ever gives me anything besides 'no signal'. There do not appear to be any directly related dmesg errors. If I enable i915.verbose_state_checks=1 then I do get a stream of messages, but I don't see anything obviously wrong, although I don't understand most of it.

In addition, I've found that if I run with nomodeset or i915.modeset=0 and set the EFI to boot using the external display, then the HDMI output will work, but then I am stuck routing everything through the very limited fb drivers.

The laptop additionally provides two USB-C connectors which show up as DP-1 and DP-2. Both of these result in 'No signal' as well, however unlike the HDMI output I get an error in dmesg about

"[ 3049.558501] [drm:intel_dp_start_link_train [i915]] *ERROR* failed to enable link training"

Kernel:

Linux excalibur 5.6.15-arch1-1 #1 SMP PREEMPT Wed, 27 May 2020 23:42:26 +0000 x86_64 GNU/Linux

Thanks.

[AndrewG_Intel]

Hello spease

Thank you for posting on the Intel® communities.

Most Linux-based* distributions include Intel® Graphics Drivers. These drivers are provided and maintained by the Linux* distribution vendors. Contact your operating system vendor (OSV) and use their distribution for driver access and support.

Intel does not provide direct downloads and technical support for Linux drivers. The Intel Graphics Linux driver is primarily supported through the original equipment manufacturer (OEM), the Linux distribution vendor, or by the Intel Open Source Technology Center at 01.org/linuxgraphics. For more information, please review the following links:

How to Find Graphics Drivers for Linux*

Supported Operating Systems for Intel® Graphics Products

Best regards,

Andrew G.

Intel Customer Support Technician