If the crtc is active, we can simply flip a new fb onto it, provided the
other mode setting reqs are met. Otherwise, we'll need to do a full
mode set to re-enable the crtc.
v2: check for crtc active and set mode_changed accordingly
v3: add module parameter, i915.fastboot, to control no fb -> fb flip behavior
Signed-off-by: Jesse Barnes <jbarnes at virtuousgeek.org>
---
drivers/gpu/drm/i915/intel_display.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index a55e1e5..0e7324d 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -8667,8 +8667,16 @@ intel_set_config_compute_mode_changes(struct drm_mode_set *set,
if (set->crtc->fb != set->fb) {
/* If we have no fb then treat it as a full mode set */
if (set->crtc->fb == NULL) {
- DRM_DEBUG_KMS("crtc has no fb, full mode set\n");
- config->mode_changed = true;
+ struct intel_crtc *intel_crtc =
+ to_intel_crtc(set->crtc);
+
+ if (intel_crtc->active && i915_fastboot) {
+ DRM_DEBUG_KMS("crtc has no fb, will flip\n");
+ config->fb_changed = true;
+ } else {
+ DRM_DEBUG_KMS("inactive crtc, full mode set\n");
+ config->mode_changed = true;
+ }
} else if (set->fb == NULL) {
config->mode_changed = true;
} else if (set->fb->pixel_format !=
--
1.7.9.5
