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: Rob Clark <rob@ti.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
This commit is contained in:
Rob Clark 2012-10-16 22:48:40 +00:00 committed by Dave Airlie
parent edec4af4c3
commit c6eefa1750
3 changed files with 59 additions and 37 deletions

View File

@ -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>

View File

@ -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);

View File

@ -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);