Simon Ser 324eeaa0cd backend/drm: disable all CRTCs after VT switch ... When the user switches away from the VT where wlroots is running, the new DRM master may mutate the KMS state in an arbitrary manner. For instance, let's say wlroots uses the following connector/CRTC mapping: - CRTC 42 drives connector DP-1 - CRTC 43 drives connector DP-2 Then the new DRM master may swap the mapping like so: - CRTC 42 drives connector DP-2 - CRTC 43 drives connector DP-1 wlroots needs to restore its own state when the user switches back. Some state is attached to wlr_drm_crtc (e.g. current FB), so reading back and adopting the CRTC/connector mapping left by the previous DRM master would be complicated (this was the source of other bugs in the past, see [1]). With the previous logic, wlroots merely tries to restore the state of each connector one after the other. This fails in the scenario described above: the kernel refuses to use CRTC 42 for DP-1, because that CRTC is already in-use for DP-2. Unfortunately with the legacy uAPI it's not possible to restore the state in one go. We need to support both legacy and atomic uAPIs, so let's fix the bug for the legacy uAPI first, and then improve the situation for the atomic uAPI as a second step [2]. We need to disable the CRTCs we're going to switch the connectors for. This sounds complicated, so let's just disable all CRTCs to simplify. This causes a black screen because of the on/off modesets, but makes VT switch much more reliable, so I'll take it. [1]: c6d8a11d2c [2]: https://gitlab.freedesktop.org/wlroots/wlroots/-/merge_requests/3794 Closes: https://gitlab.freedesktop.org/wlroots/wlroots/-/issues/3342		2023-01-18 18:38:21 +00:00
..
atomic.c	backend/drm: store pending FB in state	2022-12-07 17:45:59 +01:00
backend.c	backend/drm: disable all CRTCs after VT switch	2023-01-18 18:38:21 +00:00
cvt.c	backend/drm: add support for custom modes	2019-10-27 10:46:47 -04:00
drm.c	backend/drm: check return value of get_drm_{connector,crtc}_props()	2022-12-16 10:30:14 +01:00
gen_pnpids.sh	backend/drm: use pnp.ids to fetch EDID data	2022-11-09 00:25:18 +03:00
legacy.c	backend/drm: store pending FB in state	2022-12-07 17:45:59 +01:00
meson.build	backend/session: make optional	2022-11-25 16:15:29 +00:00
monitor.c	backend/drm: add wlr_drm_backend_monitor	2021-12-13 14:55:16 +01:00
properties.c	backend/drm: set "max bpc" to the max	2022-06-19 16:55:36 +00:00
renderer.c	backend/drm: store pending FB in state	2022-12-07 17:45:59 +01:00
util.c	backend/drm: add drm_connector_status_str()	2022-12-13 16:50:27 +00:00