Cannot init renderer for external monitor on i915 (Requested display configuration exceeds system DDB limitations)
This is from the debug logs, after I've plugged in an external monitor, waited, and then tried to enable via an IPC command:
2019-10-25 18:31:35 - [sway/ipc-server.c:154] Event on IPC listening socket
2019-10-25 18:31:35 - [sway/ipc-server.c:200] New client: fd 116
2019-10-25 18:31:35 - [sway/ipc-server.c:220] Client 116 readable
2019-10-25 18:31:35 - [sway/commands.c:250] Handling command 'output DP-1 enable'
2019-10-25 18:31:35 - [sway/commands.c:418] Subcommand: enable
2019-10-25 18:31:35 - [sway/config/output.c:133] Merging on top of existing id on name config
2019-10-25 18:31:35 - [sway/config/output.c:172] Merging on top of existing output config
2019-10-25 18:31:35 - [sway/config/output.c:199] Config stored for output DP-1 (enabled: 1) (3440x1440@-1.000000Hz position -1,-1 scale -1.000000 subpixel unknown transform -1) (bg #111111 solid_color) (dpms 0)
2019-10-25 18:31:35 - [backend/drm/atomic.c:57] DP-1: Atomic commit failed (modeset): Invalid argument
2019-10-25 18:31:35 - [sway/config/output.c:264] Set Dell Inc. Dell AW3418DW NDRWF78Q0G8L on DP-1 mode to 3440x1440 (-1.000000 Hz)
2019-10-25 18:31:35 - [sway/config/output.c:227] Assigning configured mode to DP-1
2019-10-25 18:31:35 - [backend/drm/drm.c:654] Modesetting 'DP-1' with '3440x1440@49987 mHz'
2019-10-25 18:31:35 - [backend/drm/drm.c:549] Initializing renderer on connector 'DP-1'
2019-10-25 18:31:35 - [backend/drm/atomic.c:57] DP-1: Atomic commit failed (modeset): Invalid argument
2019-10-25 18:31:35 - [backend/drm/drm.c:568] Page-flip failed with primary FB modifiers enabled, retrying without modifiers
2019-10-25 18:31:35 - [backend/drm/atomic.c:57] DP-1: Atomic commit failed (modeset): Invalid argument
2019-10-25 18:31:35 - [backend/drm/drm.c:577] Failed to initialize renderer on connector 'DP-1': initial page-flip failed
2019-10-25 18:31:35 - [backend/drm/drm.c:658] Failed to initialize renderer for plane
2019-10-25 18:31:35 - [sway/config/output.c:279] Failed to modeset output DP-1
2019-10-25 18:31:35 - [sway/ipc-server.c:938] Added IPC reply of type 0x0 to client 116 queue: [ { "success": true } ]
2019-10-25 18:31:35 - [sway/ipc-server.c:524] Client 116 writable
2019-10-25 18:31:35 - [sway/ipc-server.c:215] Client 116 hung up
2019-10-25 18:31:35 - [sway/ipc-server.c:554] IPC Client 116 disconnected
2019-10-25 18:31:36 - [sway/ipc-server.c:154] Event on IPC listening socket
2019-10-25 18:31:36 - [sway/ipc-server.c:200] New client: fd 116
2019-10-25 18:31:36 - [sway/ipc-server.c:220] Client 116 readable
This used to work.