drm: Initialize struct drm_crtc_state.no_vblank from device settings

 * &drm_crtc_state.connectors_changed is set when a connector is added or

 * removed from the CRTC.  &drm_crtc_state.active_changed is set when

 * &drm_crtc_state.active changes, which is used for DPMS.

 * &drm_crtc_state.no_vblank is set from the result of drm_dev_has_vblank().

 * See also: drm_atomic_crtc_needs_modeset()

 *

 * IMPORTANT:

			return -EINVAL;

		}

		if (drm_dev_has_vblank(dev))

			new_crtc_state->no_vblank = false;

		else

			new_crtc_state->no_vblank = true;

	}

	ret = handle_conflicting_encoders(state, false);

 * when a job is queued, and any change to the pipeline that does not touch the

 * connector is leading to timeouts when calling

 * drm_atomic_helper_wait_for_vblanks() or

 * drm_atomic_helper_wait_for_flip_done().

 * drm_atomic_helper_wait_for_flip_done(). In addition to writeback

 * connectors, this function can also fake VBLANK events for CRTCs without

 * VBLANK interrupt.

 *

 * This is part of the atomic helper support for nonblocking commits, see

 * drm_atomic_helper_setup_commit() for an overview.

 * &drm_driver.max_vblank_count. In that case the vblank core only disables the

 * vblanks after a timer has expired, which can be configured through the

 * ``vblankoffdelay`` module parameter.

 *

 * Drivers for hardware without support for vertical-blanking interrupts

 * must not call drm_vblank_init(). For such drivers, atomic helpers will

 * automatically generate fake vblank events as part of the display update.

 * This functionality also can be controlled by the driver by enabling and

 * disabling struct drm_crtc_state.no_vblank.

 */

/* Retry timestamp calculation up to 3 times to satisfy

}

EXPORT_SYMBOL(drm_vblank_init);

/**

 * drm_dev_has_vblank - test if vblanking has been initialized for

 *                      a device

 * @dev: the device

 *

 * Drivers may call this function to test if vblank support is

 * initialized for a device. For most hardware this means that vblanking

 * can also be enabled.

 *

 * Atomic helpers use this function to initialize

 * &drm_crtc_state.no_vblank. See also drm_atomic_helper_check_modeset().

 *

 * Returns:

 * True if vblanking has been initialized for the given device, false

 * otherwise.

 */

bool drm_dev_has_vblank(const struct drm_device *dev)

{

	return dev->num_crtcs != 0;

}

EXPORT_SYMBOL(drm_dev_has_vblank);

/**

 * drm_crtc_vblank_waitqueue - get vblank waitqueue for the CRTC

 * @crtc: which CRTC's vblank waitqueue to retrieve

	 * @no_vblank:

	 *

	 * Reflects the ability of a CRTC to send VBLANK events. This state

	 * usually depends on the pipeline configuration, and the main usuage

	 * is CRTCs feeding a writeback connector operating in oneshot mode.

	 * In this case the VBLANK event is only generated when a job is queued

	 * to the writeback connector, and we want the core to fake VBLANK

	 * events when this part of the pipeline hasn't changed but others had

	 * or when the CRTC and connectors are being disabled.

	 * usually depends on the pipeline configuration. If set to true, DRM

	 * atomic helpers will send out a fake VBLANK event during display

	 * updates after all hardware changes have been committed. This is

	 * implemented in drm_atomic_helper_fake_vblank().

	 *

	 * One usage is for drivers and/or hardware without support for VBLANK

	 * interrupts. Such drivers typically do not initialize vblanking

	 * (i.e., call drm_vblank_init() with the number of CRTCs). For CRTCs

	 * without initialized vblanking, this field is set to true in

	 * drm_atomic_helper_check_modeset(), and a fake VBLANK event will be

	 * send out on each update of the display pipeline by

	 * drm_atomic_helper_fake_vblank().

	 *

	 * Another usage is CRTCs feeding a writeback connector operating in

	 * oneshot mode. In this case the fake VBLANK event is only generated

	 * when a job is queued to the writeback connector, and we want the

	 * core to fake VBLANK events when this part of the pipeline hasn't

	 * changed but others had or when the CRTC and connectors are being

	 * disabled.

	 *

	 * __drm_atomic_helper_crtc_duplicate_state() will not reset the value

	 * from the current state, the CRTC driver is then responsible for

	 *  - Events for disabled CRTCs are not allowed, and drivers can ignore

	 *    that case.

	 *

	 * This can be handled by the drm_crtc_send_vblank_event() function,

	 * For very simple hardware without VBLANK interrupt, enabling

	 * &struct drm_crtc_state.no_vblank makes DRM's atomic commit helpers

	 * send a fake VBLANK event at the end of the display update after all

	 * hardware changes have been applied. See

	 * drm_atomic_helper_fake_vblank().

	 *

	 * For more complex hardware this

	 * can be handled by the drm_crtc_send_vblank_event() function,

	 * which the driver should call on the provided event upon completion of

	 * the atomic commit. Note that if the driver supports vblank signalling

	 * and timestamping the vblank counters and timestamps must agree with

	 * This is the function drivers should submit the

	 * &drm_pending_vblank_event from. Using either

	 * drm_crtc_arm_vblank_event(), when the driver supports vblank

	 * interrupt handling, or drm_crtc_send_vblank_event() directly in case

	 * the hardware lacks vblank support entirely.

	 * interrupt handling, or drm_crtc_send_vblank_event() for more

	 * complex case. In case the hardware lacks vblank support entirely,

	 * drivers can set &struct drm_crtc_state.no_vblank in

	 * &struct drm_simple_display_pipe_funcs.check and let DRM's

	 * atomic helper fake a vblank event.

	 */

	void (*update)(struct drm_simple_display_pipe *pipe,

		       struct drm_plane_state *old_plane_state);

};

int drm_vblank_init(struct drm_device *dev, unsigned int num_crtcs);

bool drm_dev_has_vblank(const struct drm_device *dev);

u64 drm_crtc_vblank_count(struct drm_crtc *crtc);

u64 drm_crtc_vblank_count_and_time(struct drm_crtc *crtc,

				   ktime_t *vblanktime);