OpenE2K/linux
6
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

media: cec: rework the cec event handling

Browse Source 
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
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

110
drivers/media/cec/cec-adap.c
View File

@ -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 (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->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;
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;
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;
}
/*
* 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 (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,
},
};
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);
/*
* if the queue now has more than CEC_MAX_MSG_RX_QUEUE_SZ
* messages, drop the oldest one and send a lost message event.
*/
if (fh->queued_msgs == CEC_MAX_MSG_RX_QUEUE_SZ) {
list_del(&entry->list);
goto lost_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;
}
lost_msgs:
/*
* 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);
cec_queue_event_fh(fh, &ev_lost_msg, 0);
/*
* We lost a message, either because kmalloc failed or the queue
* was full.
*/
cec_queue_event_fh(fh, &ev_lost_msgs, ktime_get_ns());
}
/*

48
drivers/media/cec/cec-api.c
View File

@ -57,7 +57,7 @@ static unsigned int cec_poll(struct file *filp,
res |= POLLOUT | POLLWRNORM;
if (fh->queued_msgs)
res |= POLLIN | POLLRDNORM;
if (fh->pending_events)
if (fh->total_queued_events)
res |= POLLPRI;
poll_wait(filp, &fh->wait, poll);
mutex_unlock(&adap->lock);
@ -289,15 +289,17 @@ static long cec_receive(struct cec_adapter *adap, struct cec_fh *fh,
static long cec_dqevent(struct cec_adapter *adap, struct cec_fh *fh,
bool block, struct cec_event __user *parg)
{
struct cec_event *ev = NULL;
struct cec_event_entry *ev = NULL;
u64 ts = ~0ULL;
unsigned int i;
unsigned int ev_idx;
long err = 0;
mutex_lock(&fh->lock);
while (!fh->pending_events && block) {
while (!fh->total_queued_events && block) {
mutex_unlock(&fh->lock);
err = wait_event_interruptible(fh->wait, fh->pending_events);
err = wait_event_interruptible(fh->wait,
fh->total_queued_events);
if (err)
return err;
mutex_lock(&fh->lock);
@ -305,23 +307,29 @@ static long cec_dqevent(struct cec_adapter *adap, struct cec_fh *fh,
/* Find the oldest event */
for (i = 0; i < CEC_NUM_EVENTS; i++) {
if (fh->pending_events & (1 << (i + 1)) &&
fh->events[i].ts <= ts) {
ev = &fh->events[i];
ts = ev->ts;
struct cec_event_entry *entry =
list_first_entry_or_null(&fh->events[i],
struct cec_event_entry, list);
if (entry && entry->ev.ts <= ts) {
ev = entry;
ev_idx = i;
ts = ev->ev.ts;
}
}
if (!ev) {
err = -EAGAIN;
goto unlock;
}
list_del(&ev->list);
if (copy_to_user(parg, ev, sizeof(*ev))) {
if (copy_to_user(parg, &ev->ev, sizeof(ev->ev)))
err = -EFAULT;
goto unlock;
}
fh->pending_events &= ~(1 << ev->event);
if (ev_idx >= CEC_NUM_CORE_EVENTS)
kfree(ev);
fh->queued_events[ev_idx]--;
fh->total_queued_events--;
unlock:
mutex_unlock(&fh->lock);
@ -495,6 +503,7 @@ static int cec_open(struct inode *inode, struct file *filp)
.event = CEC_EVENT_STATE_CHANGE,
.flags = CEC_EVENT_FL_INITIAL_STATE,
};
unsigned int i;
int err;
if (!fh)
@ -502,6 +511,8 @@ static int cec_open(struct inode *inode, struct file *filp)
INIT_LIST_HEAD(&fh->msgs);
INIT_LIST_HEAD(&fh->xfer_list);
for (i = 0; i < CEC_NUM_EVENTS; i++)
INIT_LIST_HEAD(&fh->events[i]);
mutex_init(&fh->lock);
init_waitqueue_head(&fh->wait);
@ -544,6 +555,7 @@ static int cec_release(struct inode *inode, struct file *filp)
struct cec_devnode *devnode = cec_devnode_data(filp);
struct cec_adapter *adap = to_cec_adapter(devnode);
struct cec_fh *fh = filp->private_data;
unsigned int i;
mutex_lock(&adap->lock);
if (adap->cec_initiator == fh)
@ -585,6 +597,16 @@ static int cec_release(struct inode *inode, struct file *filp)
list_del(&entry->list);
kfree(entry);
}
for (i = CEC_NUM_CORE_EVENTS; i < CEC_NUM_EVENTS; i++) {
while (!list_empty(&fh->events[i])) {
struct cec_event_entry *entry =
list_first_entry(&fh->events[i],
struct cec_event_entry, list);
list_del(&entry->list);
kfree(entry);
}
}
kfree(fh);
cec_put_device(devnode);

14
include/media/cec.h
View File

@ -81,7 +81,13 @@ struct cec_msg_entry {
struct cec_msg msg;
};
#define CEC_NUM_EVENTS CEC_EVENT_LOST_MSGS
struct cec_event_entry {
struct list_head list;
struct cec_event ev;
};
#define CEC_NUM_CORE_EVENTS 2
#define CEC_NUM_EVENTS CEC_EVENT_PIN_HIGH
struct cec_fh {
struct list_head list;
@ -92,9 +98,11 @@ struct cec_fh {
/* Events */
wait_queue_head_t wait;
unsigned int pending_events;
struct cec_event events[CEC_NUM_EVENTS];
struct mutex lock;
struct list_head events[CEC_NUM_EVENTS]; /* queued events */
u8 queued_events[CEC_NUM_EVENTS];
unsigned int total_queued_events;
struct cec_event_entry core_events[CEC_NUM_CORE_EVENTS];
struct list_head msgs; /* queued messages */
unsigned int queued_msgs;
};

3
include/uapi/linux/cec.h
View File

@ -412,6 +412,7 @@ struct cec_log_addrs {
#define CEC_EVENT_PIN_HIGH 4
#define CEC_EVENT_FL_INITIAL_STATE (1 << 0)
#define CEC_EVENT_FL_DROPPED_EVENTS (1 << 1)
/**
* struct cec_event_state_change - used when the CEC adapter changes state.
@ -424,7 +425,7 @@ struct cec_event_state_change {
};
/**
* struct cec_event_lost_msgs - tells you how many messages were lost due.
* struct cec_event_lost_msgs - tells you how many messages were lost.
* @lost_msgs: how many messages were lost.
*/
struct cec_event_lost_msgs {