To whom it may concern: Based on the Wiki page https://www.x.org/wiki/RadeonFeature/ indicating that DCN3.0 supported 4-6 display controllers and PLLs, I purchased a Beige Goby card. However, after installing the card, xrandr showed only 2 available crtcs, and I was unable to complete the triple-head setup I had been planning. I took a dive into the kernel code, and discovered that DCN3.0 actually breaks down into DCN3.0, 3.01, 3.02, and 3.03. Beige Goby is the lattermost of these, and it has only two timing generators -- thus limiting it to driving two displays.
Being a wiki, I would normally correct the contents myself, but the process for accessing that wiki appears more involved than I'm willing to attempt. As such, I'm respectfully requesting here that someone with access please take either of the following actions: - Edit the DCN3.0 entry to indicate 2-6 cores, instead of 4-6, or - Break out the entries: -- DCN3.0 (Sienna Cichlid, Navy Flounder) -> 6 -- DCN3.01 (Vangogh) -> 4 -- DCN3.02 (Dimgray Cavefish) -> 5 -- DCN3.03 (Beige Goby) -> 2 For the latter claims, recent Linux kernel sources can be searched -- I happened to use the Gentoo patched version of 5.15.59. A switch statement maps chips -> DCN version in the function dm_dmub_sw_init (drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c). The resource limits can be found via searching for ".num_timing_generator =", which turns up 6 for dce30_resources.c, 4 for dce301_resources.c, 5 for dce302_resources.c, and 2 for dce303_resources.c. Thank you for your time.
