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/i915_drv.c | 5 +++++ drivers/gpu/drm/i915/i915_drv.h | 1 + drivers/gpu/drm/i915/intel_display.c | 12 ++++++++++-- 3 files changed, 16 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c index a1a936f..cf266dc 100644 --- a/drivers/gpu/drm/i915/i915_drv.c +++ b/drivers/gpu/drm/i915/i915_drv.c @@ -128,6 +128,11 @@ module_param_named(disable_power_well, i915_disable_power_well, int, 0600); MODULE_PARM_DESC(disable_power_well, "Disable the power well when possible (default: false)"); +bool i915_fastboot __read_mostly = 0; +module_param_named(fastboot, i915_fastboot, bool, 0600); +MODULE_PARM_DESC(fastboot, "Try to skip unnecessary mode sets at boot time " + "(default: false)"); + static struct drm_driver driver; extern int intel_agp_enabled; diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 62f20b2..9b9b106 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -1470,6 +1470,7 @@ extern bool i915_enable_hangcheck __read_mostly; extern int i915_enable_ppgtt __read_mostly; extern unsigned int i915_preliminary_hw_support __read_mostly; extern int i915_disable_power_well __read_mostly; +extern bool i915_fastboot __read_mostly; extern int i915_suspend(struct drm_device *dev, pm_message_t state); extern int i915_resume(struct drm_device *dev); diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 80b70dc..e90df02 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -8532,8 +8532,16 @@ 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