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media: cec: rework the cec event handling

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Event handling was always fairly simplistic since there were only
two events. With the addition of pin events this needed to be redesigned.

The state_change and lost_msgs events are now core events with the
guarantee that the last state is always available. The new pin events
are a queue of events (up to 64 for each event) and the oldest event
will be dropped if the application cannot keep up. Lost events are
marked with a new event flag.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
This commit is contained in:
Hans Verkuil
2017-07-11 03:30:39 -03:00
committed by Mauro Carvalho Chehab
parent 6303d97873
commit 6b2bbb0874
4 changed files with 125 additions and 70 deletions
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130
drivers/media/cec/cec-adap.c
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@@ -78,42 +78,62 @@ static unsigned int cec_log_addr2dev(const struct cec_adapter *adap, u8 log_addr
* Queue a new event for this filehandle. If ts == 0, then set it
* to the current time.
*
* The two events that are currently defined do not need to keep track
* of intermediate events, so no actual queue of events is needed,
* instead just store the latest state and the total number of lost
* messages.
*
* Should new events be added in the future that require intermediate
* results to be queued as well, then a proper queue data structure is
* required. But until then, just keep it simple.
* We keep a queue of at most max_event events where max_event differs
* per event. If the queue becomes full, then drop the oldest event and
* keep track of how many events we've dropped.
*/
void cec_queue_event_fh(struct cec_fh *fh,
const struct cec_event *new_ev, u64 ts)
{
struct cec_event *ev = &fh->events[new_ev->event - 1];
static const u8 max_events[CEC_NUM_EVENTS] = {
1, 1, 64, 64,
};
struct cec_event_entry *entry;
unsigned int ev_idx = new_ev->event - 1;
if (WARN_ON(ev_idx >= ARRAY_SIZE(fh->events)))
return;
if (ts == 0)
ts = ktime_get_ns();
mutex_lock(&fh->lock);
if (new_ev->event == CEC_EVENT_LOST_MSGS &&
fh->pending_events & (1 << new_ev->event)) {
/*
* If there is already a lost_msgs event, then just
* update the lost_msgs count. This effectively
* merges the old and new events into one.
*/
ev->lost_msgs.lost_msgs += new_ev->lost_msgs.lost_msgs;
goto unlock;
}
if (ev_idx < CEC_NUM_CORE_EVENTS)
entry = &fh->core_events[ev_idx];
else
entry = kmalloc(sizeof(*entry), GFP_KERNEL);
if (entry) {
if (new_ev->event == CEC_EVENT_LOST_MSGS &&
fh->queued_events[ev_idx]) {
entry->ev.lost_msgs.lost_msgs +=
new_ev->lost_msgs.lost_msgs;
goto unlock;
}
entry->ev = *new_ev;
entry->ev.ts = ts;
/*
* Intermediate states are not interesting, so just
* overwrite any older event.
*/
*ev = *new_ev;
ev->ts = ts;
fh->pending_events |= 1 << new_ev->event;
if (fh->queued_events[ev_idx] < max_events[ev_idx]) {
/* Add new msg at the end of the queue */
list_add_tail(&entry->list, &fh->events[ev_idx]);
fh->queued_events[ev_idx]++;
fh->total_queued_events++;
goto unlock;
}
if (ev_idx >= CEC_NUM_CORE_EVENTS) {
list_add_tail(&entry->list, &fh->events[ev_idx]);
/* drop the oldest event */
entry = list_first_entry(&fh->events[ev_idx],
struct cec_event_entry, list);
list_del(&entry->list);
kfree(entry);
}
}
/* Mark that events were lost */
entry = list_first_entry_or_null(&fh->events[ev_idx],
struct cec_event_entry, list);
if (entry)
entry->ev.flags |= CEC_EVENT_FL_DROPPED_EVENTS;
unlock:
mutex_unlock(&fh->lock);
@@ -134,46 +154,50 @@ static void cec_queue_event(struct cec_adapter *adap,
}
/*
* Queue a new message for this filehandle. If there is no more room
* in the queue, then send the LOST_MSGS event instead.
* Queue a new message for this filehandle.
*
* We keep a queue of at most CEC_MAX_MSG_RX_QUEUE_SZ messages. If the
* queue becomes full, then drop the oldest message and keep track
* of how many messages we've dropped.
*/
static void cec_queue_msg_fh(struct cec_fh *fh, const struct cec_msg *msg)
{
static const struct cec_event ev_lost_msg = {
.ts = 0,
static const struct cec_event ev_lost_msgs = {
.event = CEC_EVENT_LOST_MSGS,
.flags = 0,
{
.lost_msgs.lost_msgs = 1,
},
.lost_msgs.lost_msgs = 1,
};
struct cec_msg_entry *entry;
mutex_lock(&fh->lock);
entry = kmalloc(sizeof(*entry), GFP_KERNEL);
if (!entry)
goto lost_msgs;
if (entry) {
entry->msg = *msg;
/* Add new msg at the end of the queue */
list_add_tail(&entry->list, &fh->msgs);
entry->msg = *msg;
/* Add new msg at the end of the queue */
list_add_tail(&entry->list, &fh->msgs);
if (fh->queued_msgs < CEC_MAX_MSG_RX_QUEUE_SZ) {
/* All is fine if there is enough room */
fh->queued_msgs++;
mutex_unlock(&fh->lock);
wake_up_interruptible(&fh->wait);
return;
}
/*
* if the message queue is full, then drop the oldest one and
* send a lost message event.
*/
entry = list_first_entry(&fh->msgs, struct cec_msg_entry, list);
list_del(&entry->list);
kfree(entry);
}
mutex_unlock(&fh->lock);
/*
* if the queue now has more than CEC_MAX_MSG_RX_QUEUE_SZ
* messages, drop the oldest one and send a lost message event.
* We lost a message, either because kmalloc failed or the queue
* was full.
*/
if (fh->queued_msgs == CEC_MAX_MSG_RX_QUEUE_SZ) {
list_del(&entry->list);
goto lost_msgs;
}
fh->queued_msgs++;
mutex_unlock(&fh->lock);
wake_up_interruptible(&fh->wait);
return;
lost_msgs:
mutex_unlock(&fh->lock);
cec_queue_event_fh(fh, &ev_lost_msg, 0);
cec_queue_event_fh(fh, &ev_lost_msgs, ktime_get_ns());
}
/*