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| author | Hans Verkuil <hans.verkuil@cisco.com> | 2018-03-06 16:20:00 -0500 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@s-opensource.com> | 2018-03-22 08:16:52 -0400 |
| commit | 6ec1cbf6b12531a794bbc007fbf6e74edf7fc93c (patch) | |
| tree | 50394a5dd5d61aa5377bc05ffbc02da3d1a19308 /include/media/cec.h | |
| parent | 2b76e5392d0647c35226b464269b87026578ea83 (diff) | |
| download | lwn-6ec1cbf6b12531a794bbc007fbf6e74edf7fc93c.tar.gz lwn-6ec1cbf6b12531a794bbc007fbf6e74edf7fc93c.zip | |
media: cec: improve CEC pin event handling
It turns out that the struct cec_fh event buffer size of 64 events
(64 for CEC_EVENT_PIN_CEC_LOW and 64 for _HIGH) is too small. It's
about 160 ms worth of events and if the Raspberry Pi is busy, then it
might take too long for the application to be scheduled so that it can
drain the pending events. Increase these buffers to 800 events which
is at least 2 seconds worth of events.
There is also a FIFO in between the interrupt and the cec-pin thread.
The thread passes the events on to the CEC core. It is important that
should this FIFO fill up the cec core will be informed that events
have been lost so this can be communicated to the user by setting
CEC_EVENT_FL_DROPPED_EVENTS.
It is very hard to debug CEC problems if events were lost without
informing the user of that fact.
If events were dropped due to the FIFO filling up, then the debugfs
status file will let you know how many events were dropped.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Diffstat (limited to 'include/media/cec.h')
| -rw-r--r-- | include/media/cec.h | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/include/media/cec.h b/include/media/cec.h index 41df048efc55..580ab1042898 100644 --- a/include/media/cec.h +++ b/include/media/cec.h @@ -92,7 +92,7 @@ struct cec_fh { wait_queue_head_t wait; struct mutex lock; struct list_head events[CEC_NUM_EVENTS]; /* queued events */ - u8 queued_events[CEC_NUM_EVENTS]; + u16 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 */ @@ -291,11 +291,12 @@ static inline void cec_received_msg(struct cec_adapter *adap, * * @adap: pointer to the cec adapter * @is_high: when true the CEC pin is high, otherwise it is low + * @dropped_events: when true some events were dropped * @ts: the timestamp for this event * */ -void cec_queue_pin_cec_event(struct cec_adapter *adap, - bool is_high, ktime_t ts); +void cec_queue_pin_cec_event(struct cec_adapter *adap, bool is_high, + bool dropped_events, ktime_t ts); /** * cec_queue_pin_hpd_event() - queue a pin event with a given timestamp. |