https://bugs.freedesktop.org/show_bug.cgi?id=106040
Bug ID: 106040 Summary: [DC] HDMI Monitor has Overscan/Scaling Product: DRI Version: DRI git Hardware: x86-64 (AMD64) OS: Linux (All) Status: NEW Severity: normal Priority: medium Component: DRM/AMDgpu Assignee: dri-devel@lists.freedesktop.org Reporter: djbm@gnunorth.ca
Created attachment 138831 --> https://bugs.freedesktop.org/attachment.cgi?id=138831&action=edit Overscan issue on HP w2207h
With my HP w2207h monitor connected over HDMI, the image appears overscanned, it is cut off at the sides and is upscaled (see attached image, note how the top bar is missing with dc=1). It is possible to fit the image inside the monitor with xset --set underscan on and xset --set "underscan {hborder,vborder}", but this results in a blurry display.
This occurs with a RX Vega 64 and an RX 560 with amd-staging-drm-next commit 6d15a288b18119428b3af5d7a7641745e9f82860 (the latest at the time of testing) as well as mainline 4.16.0. With the RX 560, the overscanning only occurs when the new DC code is used, using the old code (with amdgpu.dc=0) results in a perfect display. This also doesn't affect any other monitor I own using HDMI.
Attached further are logs made with amdgpu.dc_log=1 and drm.debug=0x6 on the Vega 64, the 560 with amdgpu.dc=1, and the 560 with amdgpu.dc=0.