Commit c6eefa17 authored by Rob Clark's avatar Rob Clark Committed by Dave Airlie
Browse files

drm: add drm_send_vblank_event() helper (v5) 



A helper that drivers can use to send vblank event after a pageflip.
If the driver doesn't support proper vblank irq based time/seqn then
just pass -1 for the pipe # to get do_gettimestamp() behavior (since
there are a lot of drivers that don't use drm_vblank_count_and_time())

Also an internal send_vblank_event() helper for the various other code
paths within drm_irq that also need to send vblank events.

v1: original
v2: add back 'vblwait->reply.sequence = seq' which should not have
    been deleted
v3: add WARN_ON() in case lock is not held and comments
v4: use WARN_ON_SMP() instead to fix issue with !SMP && !DEBUG_SPINLOCK
    as pointed out by Marcin Slusarz
v5: update docbook

Signed-off-by: default avatarRob Clark <rob@ti.com>
Signed-off-by: default avatarDave Airlie <airlied@redhat.com>
parent edec4af4

Documentation/DocBook/drm.tmpl

+5 −15
Original line number Diff line number Diff line
@@ -1141,23 +1141,13 @@ int max_width, max_height;</synopsis> 
            the <methodname>page_flip</methodname> operation will be called with a

            non-NULL <parameter>event</parameter> argument pointing to a

            <structname>drm_pending_vblank_event</structname> instance. Upon page

            flip completion the driver must fill the

            <parameter>event</parameter>::<structfield>event</structfield>

            <structfield>sequence</structfield>, <structfield>tv_sec</structfield>

            and <structfield>tv_usec</structfield> fields with the associated

            vertical blanking count and timestamp, add the event to the

            <parameter>drm_file</parameter> list of events to be signaled, and wake

            up any waiting process. This can be performed with

            flip completion the driver must call <methodname>drm_send_vblank_event</methodname>

            to fill in the event and send to wake up any waiting processes.

            This can be performed with

            <programlisting><![CDATA[

            struct timeval now;



            event->event.sequence = drm_vblank_count_and_time(..., &now);

            event->event.tv_sec = now.tv_sec;

            event->event.tv_usec = now.tv_usec;



            spin_lock_irqsave(&dev->event_lock, flags);

            list_add_tail(&event->base.link, &event->base.file_priv->event_list);

            wake_up_interruptible(&event->base.file_priv->event_wait);

            ...

            drm_send_vblank_event(dev, pipe, event);

            spin_unlock_irqrestore(&dev->event_lock, flags);

            ]]></programlisting>

          </para>

drivers/gpu/drm/drm_irq.c

+52 −22
Original line number Diff line number Diff line
@@ -802,6 +802,46 @@ u32 drm_vblank_count_and_time(struct drm_device *dev, int crtc, 
}

EXPORT_SYMBOL(drm_vblank_count_and_time);



static void send_vblank_event(struct drm_device *dev,

		struct drm_pending_vblank_event *e,

		unsigned long seq, struct timeval *now)

{

	WARN_ON_SMP(!spin_is_locked(&dev->event_lock));

	e->event.sequence = seq;

	e->event.tv_sec = now->tv_sec;

	e->event.tv_usec = now->tv_usec;



	list_add_tail(&e->base.link,

		      &e->base.file_priv->event_list);

	wake_up_interruptible(&e->base.file_priv->event_wait);

	trace_drm_vblank_event_delivered(e->base.pid, e->pipe,

					 e->event.sequence);

}



/**

 * drm_send_vblank_event - helper to send vblank event after pageflip

 * @dev: DRM device

 * @crtc: CRTC in question

 * @e: the event to send

 *

 * Updates sequence # and timestamp on event, and sends it to userspace.

 * Caller must hold event lock.

 */

void drm_send_vblank_event(struct drm_device *dev, int crtc,

		struct drm_pending_vblank_event *e)

{

	struct timeval now;

	unsigned int seq;

	if (crtc >= 0) {

		seq = drm_vblank_count_and_time(dev, crtc, &now);

	} else {

		seq = 0;

		do_gettimeofday(&now);

	}

	send_vblank_event(dev, e, seq, &now);

}

EXPORT_SYMBOL(drm_send_vblank_event);



/**

 * drm_update_vblank_count - update the master vblank counter

 * @dev: DRM device
@@ -936,6 +976,13 @@ void drm_vblank_put(struct drm_device *dev, int crtc) 
}

EXPORT_SYMBOL(drm_vblank_put);



/**

 * drm_vblank_off - disable vblank events on a CRTC

 * @dev: DRM device

 * @crtc: CRTC in question

 *

 * Caller must hold event lock.

 */

void drm_vblank_off(struct drm_device *dev, int crtc)

{

	struct drm_pending_vblank_event *e, *t;
@@ -955,15 +1002,9 @@ void drm_vblank_off(struct drm_device *dev, int crtc) 
		DRM_DEBUG("Sending premature vblank event on disable: \

			  wanted %d, current %d\n",

			  e->event.sequence, seq);



		e->event.sequence = seq;

		e->event.tv_sec = now.tv_sec;

		e->event.tv_usec = now.tv_usec;

		list_del(&e->base.link);

		drm_vblank_put(dev, e->pipe);

		list_move_tail(&e->base.link, &e->base.file_priv->event_list);

		wake_up_interruptible(&e->base.file_priv->event_wait);

		trace_drm_vblank_event_delivered(e->base.pid, e->pipe,

						 e->event.sequence);

		send_vblank_event(dev, e, seq, &now);

	}



	spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
@@ -1107,15 +1148,9 @@ static int drm_queue_vblank_event(struct drm_device *dev, int pipe, 


	e->event.sequence = vblwait->request.sequence;

	if ((seq - vblwait->request.sequence) <= (1 << 23)) {

		e->event.sequence = seq;

		e->event.tv_sec = now.tv_sec;

		e->event.tv_usec = now.tv_usec;

		drm_vblank_put(dev, pipe);

		list_add_tail(&e->base.link, &e->base.file_priv->event_list);

		wake_up_interruptible(&e->base.file_priv->event_wait);

		send_vblank_event(dev, e, seq, &now);

		vblwait->reply.sequence = seq;

		trace_drm_vblank_event_delivered(current->pid, pipe,

						 vblwait->request.sequence);

	} else {

		/* drm_handle_vblank_events will call drm_vblank_put */

		list_add_tail(&e->base.link, &dev->vblank_event_list);
@@ -1256,14 +1291,9 @@ static void drm_handle_vblank_events(struct drm_device *dev, int crtc) 
		DRM_DEBUG("vblank event on %d, current %d\n",

			  e->event.sequence, seq);



		e->event.sequence = seq;

		e->event.tv_sec = now.tv_sec;

		e->event.tv_usec = now.tv_usec;

		list_del(&e->base.link);

		drm_vblank_put(dev, e->pipe);

		list_move_tail(&e->base.link, &e->base.file_priv->event_list);

		wake_up_interruptible(&e->base.file_priv->event_wait);

		trace_drm_vblank_event_delivered(e->base.pid, e->pipe,

						 e->event.sequence);

		send_vblank_event(dev, e, seq, &now);

	}



	spin_unlock_irqrestore(&dev->event_lock, flags);

include/drm/drmP.h

+2 −0
Original line number Diff line number Diff line
@@ -1431,6 +1431,8 @@ extern int drm_vblank_wait(struct drm_device *dev, unsigned int *vbl_seq); 
extern u32 drm_vblank_count(struct drm_device *dev, int crtc);

extern u32 drm_vblank_count_and_time(struct drm_device *dev, int crtc,

				     struct timeval *vblanktime);

extern void drm_send_vblank_event(struct drm_device *dev, int crtc,

				     struct drm_pending_vblank_event *e);

extern bool drm_handle_vblank(struct drm_device *dev, int crtc);

extern int drm_vblank_get(struct drm_device *dev, int crtc);

extern void drm_vblank_put(struct drm_device *dev, int crtc);

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