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authorHans Verkuil <hans.verkuil@cisco.com>2011-06-13 19:24:17 -0300
committerMauro Carvalho Chehab <mchehab@redhat.com>2011-07-27 17:53:31 -0300
commitf1e393de382af9b9bd2462a42bfa16b8c501d81b (patch)
tree1135a4a27166d3947ebfcf2be171efa2d8cd3228 /drivers/media
parent77068d36d8b9e9902a89b4bb01011d41926f5420 (diff)
[media] v4l2-event/ctrls/fh: allocate events per fh and per type instead of just per-fh
The driver had to decide how many events to allocate when the v4l2_fh struct was created. It was possible to add more events afterwards, but there was no way to ensure that you wouldn't miss important events if the event queue would fill up for that filehandle. In addition, once there were no more free events, any new events were simply dropped on the floor. For the control event in particular this made life very difficult since control status/value changes could just be missed if the number of allocated events and the speed at which the application read events was too low to keep up with the number of generated events. The application would have no idea what the latest state was for a control since it could have missed the latest control change. So this patch makes some major changes in how events are allocated. Instead of allocating events per-filehandle they are now allocated when subscribing an event. So for that particular event type N events (determined by the driver) are allocated. Those events are reserved for that particular event type. This ensures that you will not miss events for a particular type altogether. In addition, if there are N events in use and a new event is raised, then the oldest event is dropped and the new one is added. So the latest event is always available. This can be further improved by adding the ability to merge the state of two events together, ensuring that no data is lost at all. This will be added in the next patch. This also makes it possible to allow the user to determine the number of events that will be allocated. This is not implemented at the moment, but would be trivial. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'drivers/media')
-rw-r--r--drivers/media/video/ivtv/ivtv-fileops.c4
-rw-r--r--drivers/media/video/ivtv/ivtv-ioctl.c4
-rw-r--r--drivers/media/video/omap3isp/ispccdc.c3
-rw-r--r--drivers/media/video/omap3isp/ispstat.c3
-rw-r--r--drivers/media/video/v4l2-ctrls.c18
-rw-r--r--drivers/media/video/v4l2-event.c88
-rw-r--r--drivers/media/video/v4l2-fh.c4
-rw-r--r--drivers/media/video/v4l2-subdev.c7
-rw-r--r--drivers/media/video/vivi.c2
9 files changed, 38 insertions, 95 deletions
diff --git a/drivers/media/video/ivtv/ivtv-fileops.c b/drivers/media/video/ivtv/ivtv-fileops.c
index d4275d2460cb..38f052257f46 100644
--- a/drivers/media/video/ivtv/ivtv-fileops.c
+++ b/drivers/media/video/ivtv/ivtv-fileops.c
@@ -966,10 +966,6 @@ static int ivtv_serialized_open(struct ivtv_stream *s, struct file *filp)
return -ENOMEM;
}
v4l2_fh_init(&item->fh, s->vdev);
- if (s->type == IVTV_DEC_STREAM_TYPE_YUV ||
- s->type == IVTV_DEC_STREAM_TYPE_MPG) {
- res = v4l2_event_alloc(&item->fh, 60);
- }
if (res < 0) {
v4l2_fh_exit(&item->fh);
kfree(item);
diff --git a/drivers/media/video/ivtv/ivtv-ioctl.c b/drivers/media/video/ivtv/ivtv-ioctl.c
index ff75d07097b2..3e5c090af112 100644
--- a/drivers/media/video/ivtv/ivtv-ioctl.c
+++ b/drivers/media/video/ivtv/ivtv-ioctl.c
@@ -1450,13 +1450,11 @@ static int ivtv_subscribe_event(struct v4l2_fh *fh, struct v4l2_event_subscripti
switch (sub->type) {
case V4L2_EVENT_VSYNC:
case V4L2_EVENT_EOS:
- break;
case V4L2_EVENT_CTRL:
- return v4l2_ctrl_subscribe_fh(fh, sub, 0);
+ return v4l2_event_subscribe(fh, sub, 0);
default:
return -EINVAL;
}
- return v4l2_event_subscribe(fh, sub);
}
static int ivtv_log_status(struct file *file, void *fh)
diff --git a/drivers/media/video/omap3isp/ispccdc.c b/drivers/media/video/omap3isp/ispccdc.c
index 39d501bda636..67662470661d 100644
--- a/drivers/media/video/omap3isp/ispccdc.c
+++ b/drivers/media/video/omap3isp/ispccdc.c
@@ -1691,7 +1691,7 @@ static int ccdc_subscribe_event(struct v4l2_subdev *sd, struct v4l2_fh *fh,
if (sub->type != V4L2_EVENT_OMAP3ISP_HS_VS)
return -EINVAL;
- return v4l2_event_subscribe(fh, sub);
+ return v4l2_event_subscribe(fh, sub, OMAP3ISP_CCDC_NEVENTS);
}
static int ccdc_unsubscribe_event(struct v4l2_subdev *sd, struct v4l2_fh *fh,
@@ -2162,7 +2162,6 @@ static int ccdc_init_entities(struct isp_ccdc_device *ccdc)
sd->grp_id = 1 << 16; /* group ID for isp subdevs */
v4l2_set_subdevdata(sd, ccdc);
sd->flags |= V4L2_SUBDEV_FL_HAS_EVENTS | V4L2_SUBDEV_FL_HAS_DEVNODE;
- sd->nevents = OMAP3ISP_CCDC_NEVENTS;
pads[CCDC_PAD_SINK].flags = MEDIA_PAD_FL_SINK;
pads[CCDC_PAD_SOURCE_VP].flags = MEDIA_PAD_FL_SOURCE;
diff --git a/drivers/media/video/omap3isp/ispstat.c b/drivers/media/video/omap3isp/ispstat.c
index b44cb685236a..808065948ac1 100644
--- a/drivers/media/video/omap3isp/ispstat.c
+++ b/drivers/media/video/omap3isp/ispstat.c
@@ -1032,7 +1032,6 @@ static int isp_stat_init_entities(struct ispstat *stat, const char *name,
snprintf(subdev->name, V4L2_SUBDEV_NAME_SIZE, "OMAP3 ISP %s", name);
subdev->grp_id = 1 << 16; /* group ID for isp subdevs */
subdev->flags |= V4L2_SUBDEV_FL_HAS_EVENTS | V4L2_SUBDEV_FL_HAS_DEVNODE;
- subdev->nevents = STAT_NEVENTS;
v4l2_set_subdevdata(subdev, stat);
stat->pad.flags = MEDIA_PAD_FL_SINK;
@@ -1050,7 +1049,7 @@ int omap3isp_stat_subscribe_event(struct v4l2_subdev *subdev,
if (sub->type != stat->event_type)
return -EINVAL;
- return v4l2_event_subscribe(fh, sub);
+ return v4l2_event_subscribe(fh, sub, STAT_NEVENTS);
}
int omap3isp_stat_unsubscribe_event(struct v4l2_subdev *subdev,
diff --git a/drivers/media/video/v4l2-ctrls.c b/drivers/media/video/v4l2-ctrls.c
index b63fe2a17fce..a37e5bff4342 100644
--- a/drivers/media/video/v4l2-ctrls.c
+++ b/drivers/media/video/v4l2-ctrls.c
@@ -1011,7 +1011,6 @@ static int handler_new_ref(struct v4l2_ctrl_handler *hdl,
insertion is an O(1) operation. */
if (list_empty(&hdl->ctrl_refs) || id > node2id(hdl->ctrl_refs.prev)) {
list_add_tail(&new_ref->node, &hdl->ctrl_refs);
- hdl->nr_of_refs++;
goto insert_in_hash;
}
@@ -2051,20 +2050,3 @@ void v4l2_ctrl_del_event(struct v4l2_ctrl *ctrl,
v4l2_ctrl_unlock(ctrl);
}
EXPORT_SYMBOL(v4l2_ctrl_del_event);
-
-int v4l2_ctrl_subscribe_fh(struct v4l2_fh *fh,
- struct v4l2_event_subscription *sub, unsigned n)
-{
- struct v4l2_ctrl_handler *hdl = fh->ctrl_handler;
- int ret = 0;
-
- if (!ret) {
- if (hdl->nr_of_refs * 2 > n)
- n = hdl->nr_of_refs * 2;
- ret = v4l2_event_alloc(fh, n);
- }
- if (!ret)
- ret = v4l2_event_subscribe(fh, sub);
- return ret;
-}
-EXPORT_SYMBOL(v4l2_ctrl_subscribe_fh);
diff --git a/drivers/media/video/v4l2-event.c b/drivers/media/video/v4l2-event.c
index dc68f6085697..9e325dd3ce27 100644
--- a/drivers/media/video/v4l2-event.c
+++ b/drivers/media/video/v4l2-event.c
@@ -30,44 +30,11 @@
#include <linux/sched.h>
#include <linux/slab.h>
-static void v4l2_event_unsubscribe_all(struct v4l2_fh *fh);
-
-int v4l2_event_alloc(struct v4l2_fh *fh, unsigned int n)
-{
- unsigned long flags;
-
- while (fh->nallocated < n) {
- struct v4l2_kevent *kev;
-
- kev = kzalloc(sizeof(*kev), GFP_KERNEL);
- if (kev == NULL)
- return -ENOMEM;
-
- spin_lock_irqsave(&fh->vdev->fh_lock, flags);
- list_add_tail(&kev->list, &fh->free);
- fh->nallocated++;
- spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
- }
-
- return 0;
-}
-EXPORT_SYMBOL_GPL(v4l2_event_alloc);
-
-#define list_kfree(list, type, member) \
- while (!list_empty(list)) { \
- type *hi; \
- hi = list_first_entry(list, type, member); \
- list_del(&hi->member); \
- kfree(hi); \
- }
-
-void v4l2_event_free(struct v4l2_fh *fh)
+static unsigned sev_pos(const struct v4l2_subscribed_event *sev, unsigned idx)
{
- list_kfree(&fh->free, struct v4l2_kevent, list);
- list_kfree(&fh->available, struct v4l2_kevent, list);
- v4l2_event_unsubscribe_all(fh);
+ idx += sev->first;
+ return idx >= sev->elems ? idx - sev->elems : idx;
}
-EXPORT_SYMBOL_GPL(v4l2_event_free);
static int __v4l2_event_dequeue(struct v4l2_fh *fh, struct v4l2_event *event)
{
@@ -84,11 +51,13 @@ static int __v4l2_event_dequeue(struct v4l2_fh *fh, struct v4l2_event *event)
WARN_ON(fh->navailable == 0);
kev = list_first_entry(&fh->available, struct v4l2_kevent, list);
- list_move(&kev->list, &fh->free);
+ list_del(&kev->list);
fh->navailable--;
kev->event.pending = fh->navailable;
*event = kev->event;
+ kev->sev->first = sev_pos(kev->sev, 1);
+ kev->sev->in_use--;
spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
@@ -154,17 +123,24 @@ static void __v4l2_event_queue_fh(struct v4l2_fh *fh, const struct v4l2_event *e
fh->sequence++;
/* Do we have any free events? */
- if (list_empty(&fh->free))
- return;
+ if (sev->in_use == sev->elems) {
+ /* no, remove the oldest one */
+ kev = sev->events + sev_pos(sev, 0);
+ list_del(&kev->list);
+ sev->in_use--;
+ sev->first = sev_pos(sev, 1);
+ fh->navailable--;
+ }
/* Take one and fill it. */
- kev = list_first_entry(&fh->free, struct v4l2_kevent, list);
+ kev = sev->events + sev_pos(sev, sev->in_use);
kev->event.type = ev->type;
kev->event.u = ev->u;
kev->event.id = ev->id;
kev->event.timestamp = *ts;
kev->event.sequence = fh->sequence;
- list_move_tail(&kev->list, &fh->available);
+ sev->in_use++;
+ list_add_tail(&kev->list, &fh->available);
fh->navailable++;
@@ -209,38 +185,39 @@ int v4l2_event_pending(struct v4l2_fh *fh)
EXPORT_SYMBOL_GPL(v4l2_event_pending);
int v4l2_event_subscribe(struct v4l2_fh *fh,
- struct v4l2_event_subscription *sub)
+ struct v4l2_event_subscription *sub, unsigned elems)
{
struct v4l2_subscribed_event *sev, *found_ev;
struct v4l2_ctrl *ctrl = NULL;
unsigned long flags;
+ unsigned i;
+ if (elems < 1)
+ elems = 1;
if (sub->type == V4L2_EVENT_CTRL) {
ctrl = v4l2_ctrl_find(fh->ctrl_handler, sub->id);
if (ctrl == NULL)
return -EINVAL;
}
- sev = kzalloc(sizeof(*sev), GFP_KERNEL);
+ sev = kzalloc(sizeof(*sev) + sizeof(struct v4l2_kevent) * elems, GFP_KERNEL);
if (!sev)
return -ENOMEM;
+ for (i = 0; i < elems; i++)
+ sev->events[i].sev = sev;
+ sev->type = sub->type;
+ sev->id = sub->id;
+ sev->flags = sub->flags;
+ sev->fh = fh;
+ sev->elems = elems;
spin_lock_irqsave(&fh->vdev->fh_lock, flags);
-
found_ev = v4l2_event_subscribed(fh, sub->type, sub->id);
- if (!found_ev) {
- INIT_LIST_HEAD(&sev->list);
- sev->type = sub->type;
- sev->id = sub->id;
- sev->fh = fh;
- sev->flags = sub->flags;
-
+ if (!found_ev)
list_add(&sev->list, &fh->subscribed);
- }
-
spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
- /* v4l2_ctrl_add_fh uses a mutex, so do this outside the spin lock */
+ /* v4l2_ctrl_add_event uses a mutex, so do this outside the spin lock */
if (found_ev)
kfree(sev);
else if (ctrl)
@@ -250,7 +227,7 @@ int v4l2_event_subscribe(struct v4l2_fh *fh,
}
EXPORT_SYMBOL_GPL(v4l2_event_subscribe);
-static void v4l2_event_unsubscribe_all(struct v4l2_fh *fh)
+void v4l2_event_unsubscribe_all(struct v4l2_fh *fh)
{
struct v4l2_event_subscription sub;
struct v4l2_subscribed_event *sev;
@@ -271,6 +248,7 @@ static void v4l2_event_unsubscribe_all(struct v4l2_fh *fh)
v4l2_event_unsubscribe(fh, &sub);
} while (sev);
}
+EXPORT_SYMBOL_GPL(v4l2_event_unsubscribe_all);
int v4l2_event_unsubscribe(struct v4l2_fh *fh,
struct v4l2_event_subscription *sub)
diff --git a/drivers/media/video/v4l2-fh.c b/drivers/media/video/v4l2-fh.c
index 333b8c8f40d6..122822d2b8b2 100644
--- a/drivers/media/video/v4l2-fh.c
+++ b/drivers/media/video/v4l2-fh.c
@@ -37,9 +37,7 @@ void v4l2_fh_init(struct v4l2_fh *fh, struct video_device *vdev)
INIT_LIST_HEAD(&fh->list);
set_bit(V4L2_FL_USES_V4L2_FH, &fh->vdev->flags);
fh->prio = V4L2_PRIORITY_UNSET;
-
init_waitqueue_head(&fh->wait);
- INIT_LIST_HEAD(&fh->free);
INIT_LIST_HEAD(&fh->available);
INIT_LIST_HEAD(&fh->subscribed);
fh->sequence = -1;
@@ -88,7 +86,7 @@ void v4l2_fh_exit(struct v4l2_fh *fh)
{
if (fh->vdev == NULL)
return;
- v4l2_event_free(fh);
+ v4l2_event_unsubscribe_all(fh);
fh->vdev = NULL;
}
EXPORT_SYMBOL_GPL(v4l2_fh_exit);
diff --git a/drivers/media/video/v4l2-subdev.c b/drivers/media/video/v4l2-subdev.c
index 3b67a8584916..b7967c9dc4ae 100644
--- a/drivers/media/video/v4l2-subdev.c
+++ b/drivers/media/video/v4l2-subdev.c
@@ -76,13 +76,6 @@ static int subdev_open(struct file *file)
}
v4l2_fh_init(&subdev_fh->vfh, vdev);
-
- if (sd->flags & V4L2_SUBDEV_FL_HAS_EVENTS) {
- ret = v4l2_event_alloc(&subdev_fh->vfh, sd->nevents);
- if (ret)
- goto err;
- }
-
v4l2_fh_add(&subdev_fh->vfh);
file->private_data = &subdev_fh->vfh;
#if defined(CONFIG_MEDIA_CONTROLLER)
diff --git a/drivers/media/video/vivi.c b/drivers/media/video/vivi.c
index 1b90713b44c5..cc1cf6b17183 100644
--- a/drivers/media/video/vivi.c
+++ b/drivers/media/video/vivi.c
@@ -993,7 +993,7 @@ static int vidioc_subscribe_event(struct v4l2_fh *fh,
{
switch (sub->type) {
case V4L2_EVENT_CTRL:
- return v4l2_ctrl_subscribe_fh(fh, sub, 0);
+ return v4l2_event_subscribe(fh, sub, 0);
default:
return -EINVAL;
}

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