https://bugzilla.suse.com/show_bug.cgi?id=1234055 https://bugzilla.suse.com/show_bug.cgi?id=1234055#c30 --- Comment #30 from Patrik Jakobsson <patrik.jakobsson@suse.com> --- (In reply to Otrebor Igorig from comment #29)

Unplugging every other device but the two monitors from the dock does not help. The effect is still the same.

I'm no hardware expert, but the notebook and the dock are recent enough models that should cover the required bandwidth with ease.

In fact, the dock is sold with the advertisement of being able to serve four monitors (1xHDMI, 2xDP, 1xUSB-C). And the test with another notebook showed that serving the two monitors with both in resolution 3840x2160 works. So I would exclude the dock from the problem domain.

The notebook specs linked above by Intel also suggest that this should work. The notebook and the dock are linked by a Thunderbolt 4 spec cable, which also should support this setup. So, where does this bandwidth limitation come from?

Yes, it should work with the setup you have. I believe the DP MST calculation in the i915 driver is the problem. It doesn't find enough bandwidth for the setup which makes me thing the bandwidth calculation is wrong. It could also be a problem in the Thunderbolt driver. Hopefully we can find the fix in newer kernels. If you have a HDMI cable of decent quality you can try connecting one of the displays with HDMI and the other with DP (try both ports). That should eliminate the need for DP MST to be used. It might be a workaround while we search for the real fix. -- You are receiving this mail because: You are the assignee for the bug.