From 443a38bd3f62864677779e983d7f565d41054d25 Mon Sep 17 00:00:00 2001 From: emersion Date: Sun, 28 Oct 2018 23:43:21 +0100 Subject: [PATCH] backend/drm: add WLR_DRM_NO_ATOMIC_GAMMA env variable This allows the legacy interface to be used instead of atomic if needed. This is a workaround to make some Intel GPUs work (if this variable is unset) as well as to make some AMD GPUs work (if this variable is set). --- backend/drm/atomic.c | 10 ++++++---- docs/env_vars.md | 2 ++ 2 files changed, 8 insertions(+), 4 deletions(-) diff --git a/backend/drm/atomic.c b/backend/drm/atomic.c index ad80f2fd..fc649d68 100644 --- a/backend/drm/atomic.c +++ b/backend/drm/atomic.c @@ -208,10 +208,12 @@ static bool atomic_crtc_set_gamma(struct wlr_drm_backend *drm, struct wlr_drm_crtc *crtc, size_t size, uint16_t *r, uint16_t *g, uint16_t *b) { // Fallback to legacy gamma interface when gamma properties are not available - // (can happen on older intel gpu's that support gamma but not degamma) - // TEMP: This is broken on AMDGPU. Always fallback to legacy until they get - // it fixed. Ref https://bugs.freedesktop.org/show_bug.cgi?id=107459 - if (crtc->props.gamma_lut == 0 || true) { + // (can happen on older Intel GPUs that support gamma but not degamma). + // TEMP: This is broken on AMDGPU. Provide a fallback to legacy until they + // get it fixed. Ref https://bugs.freedesktop.org/show_bug.cgi?id=107459 + const char *no_atomic_str = getenv("WLR_DRM_NO_ATOMIC_GAMMA"); + bool no_atomic = no_atomic_str != NULL && strcmp(no_atomic_str, "1") == 0; + if (crtc->props.gamma_lut == 0 || no_atomic) { return legacy_iface.crtc_set_gamma(drm, crtc, size, r, g, b); } diff --git a/docs/env_vars.md b/docs/env_vars.md index 1b1a5fd6..b67d1652 100644 --- a/docs/env_vars.md +++ b/docs/env_vars.md @@ -7,6 +7,8 @@ wlroots specific considered the primary DRM device. * *WLR_DRM_NO_ATOMIC*: set to 1 to use legacy DRM interface instead of atomic mode setting +* *WLR_DRM_NO_ATOMIC_GAMMA*: set to 1 to use legacy DRM interface for gamma + control instead of the atomic interface * *WLR_LIBINPUT_NO_DEVICES*: set to 1 to not fail without any input devices * *WLR_BACKENDS*: comma-separated list of backends to use (available backends: wayland, x11, headless)