Bug 110780 - RX 580 and 5K displays, bandwidth validation failed with multiple monitors
Summary: RX 580 and 5K displays, bandwidth validation failed with multiple monitors
Alias: None
Product: DRI
Classification: Unclassified
Component: DRM/AMDgpu (show other bugs)
Version: unspecified
Hardware: All Linux (All)
: medium major
Assignee: Default DRI bug account
QA Contact:
Depends on:
Reported: 2019-05-28 08:30 UTC by Gaël HERMET
Modified: 2019-11-19 09:29 UTC (History)
3 users (show)

See Also:
i915 platform:
i915 features:


Description Gaël HERMET 2019-05-28 08:30:23 UTC
I have been facing an issue with my 5K display (iiyama ProLite XB2779QQS-S1).

It works fine as long as it is the only active monitor, as soon as I activate another monitor the main one (5k) can't display more than 4k.

Debug using "echo 0x4 > /sys/module/drm/parameters/debug" show this :
mai 23 09:01:22 bureau-gael /usr/lib/gdm3/gdm-x-session[3465]: (EE) AMDGPU(0): failed to set mode: Invalid argument
mai 23 09:01:22 bureau-gael kernel: [drm:dce112_validate_bandwidth [amdgpu]] dce112_validate_bandwidth: Bandwidth validation failed!

I disabled the check by forcing is_display_configuration_supported to return true in dce_calcs.c and it works fine.

I tried a lot of kernel (includig drm-tip and 5.2-rc1) and they all have the same issue.
My custom kernel with no validation is based on Ubuntu's 5.0.0-15-generic.

If I can help by providing more logs or test something ask and I will do my best.
Comment 1 Martin Peres 2019-11-19 09:29:29 UTC
-- GitLab Migration Automatic Message --

This bug has been migrated to freedesktop.org's GitLab instance and has been closed from further activity.

You can subscribe and participate further through the new bug through this link to our GitLab instance: https://gitlab.freedesktop.org/drm/amd/issues/806.

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