[PATCH 04/21] staging:iio: remove ability to escalate events.

From: Jonathan Cameron
Date: Thu Mar 31 2011 - 10:53:04 EST


Whilst it is possible to output events to say buffers have passed
a particular level there are no obvious reasons to actually do so.

The upshot of this patch is that buffers will only ever have
one threshold turned on at a time.

This will need to propogated into some drivers (e.g. sca3000)

Signed-off-by: Jonathan Cameron <jic23@xxxxxxxxx>
---
drivers/staging/iio/chrdev.h | 13 -------------
drivers/staging/iio/iio.h | 16 ++--------------
drivers/staging/iio/industrialio-core.c | 30 ++----------------------------
drivers/staging/iio/industrialio-ring.c | 23 ++---------------------
drivers/staging/iio/ring_generic.h | 3 ---
drivers/staging/iio/ring_sw.c | 14 +-------------
6 files changed, 7 insertions(+), 92 deletions(-)

diff --git a/drivers/staging/iio/chrdev.h b/drivers/staging/iio/chrdev.h
index 95b439e..c1e86a9 100644
--- a/drivers/staging/iio/chrdev.h
+++ b/drivers/staging/iio/chrdev.h
@@ -45,23 +45,10 @@ struct iio_event_data {
* struct iio_detected_event_list - list element for events that have occured
* @list: linked list header
* @ev: the event itself
- * @shared_pointer: used when the event is shared - i.e. can be escallated
- * on demand (eg ring buffer 50%->100% full)
*/
struct iio_detected_event_list {
struct list_head list;
struct iio_event_data ev;
- struct iio_shared_ev_pointer *shared_pointer;
-};
-/**
- * struct iio_shared_ev_pointer - allows shared events to identify if currently
- * in the detected event list
- * @ev_p: pointer to detected event list element (null if not in list)
- * @lock: protect this element to prevent simultaneous edit and remove
- */
-struct iio_shared_ev_pointer {
- struct iio_detected_event_list *ev_p;
- spinlock_t lock;
};

/**
diff --git a/drivers/staging/iio/iio.h b/drivers/staging/iio/iio.h
index 578d078..1496f0b 100644
--- a/drivers/staging/iio/iio.h
+++ b/drivers/staging/iio/iio.h
@@ -346,22 +346,10 @@ int iio_push_event(struct iio_dev *dev_info,
* @ev_int: the event interface to which we are pushing the event
* @ev_code: the outgoing event code
* @timestamp: timestamp of the event
- * @shared_pointer_p: the shared event pointer
**/
int __iio_push_event(struct iio_event_interface *ev_int,
- int ev_code,
- s64 timestamp,
- struct iio_shared_ev_pointer*
- shared_pointer_p);
-/**
- * __iio_change_event() - change an event code in case of event escalation
- * @ev: the event to be changed
- * @ev_code: new event code
- * @timestamp: new timestamp
- **/
-void __iio_change_event(struct iio_detected_event_list *ev,
- int ev_code,
- s64 timestamp);
+ int ev_code,
+ s64 timestamp);

/**
* iio_setup_ev_int() - configure an event interface (chrdev)
diff --git a/drivers/staging/iio/industrialio-core.c b/drivers/staging/iio/industrialio-core.c
index 809588f..5b7b5df 100644
--- a/drivers/staging/iio/industrialio-core.c
+++ b/drivers/staging/iio/industrialio-core.c
@@ -66,15 +66,6 @@ static const char * const iio_chan_info_postfix[] = {
[IIO_CHAN_INFO_CALIBBIAS_SHARED/2] = "calibbias",
};

-void __iio_change_event(struct iio_detected_event_list *ev,
- int ev_code,
- s64 timestamp)
-{
- ev->ev.id = ev_code;
- ev->ev.timestamp = timestamp;
-}
-EXPORT_SYMBOL(__iio_change_event);
-
/* Used both in the interrupt line put events and the ring buffer ones */

/* Note that in it's current form someone has to be listening before events
@@ -83,9 +74,7 @@ EXPORT_SYMBOL(__iio_change_event);
*/
int __iio_push_event(struct iio_event_interface *ev_int,
int ev_code,
- s64 timestamp,
- struct iio_shared_ev_pointer *
- shared_pointer_p)
+ s64 timestamp)
{
struct iio_detected_event_list *ev;
int ret = 0;
@@ -105,9 +94,6 @@ int __iio_push_event(struct iio_event_interface *ev_int,
}
ev->ev.id = ev_code;
ev->ev.timestamp = timestamp;
- ev->shared_pointer = shared_pointer_p;
- if (ev->shared_pointer)
- shared_pointer_p->ev_p = ev;

list_add_tail(&ev->list, &ev_int->det_events.list);
ev_int->current_events++;
@@ -127,7 +113,7 @@ int iio_push_event(struct iio_dev *dev_info,
s64 timestamp)
{
return __iio_push_event(&dev_info->event_interfaces[ev_line],
- ev_code, timestamp, NULL);
+ ev_code, timestamp);
}
EXPORT_SYMBOL(iio_push_event);

@@ -295,18 +281,6 @@ static ssize_t iio_event_chrdev_read(struct file *filep,
list_del(&el->list);
ev_int->current_events--;
mutex_unlock(&ev_int->event_list_lock);
- /*
- * Possible concurency issue if an update of this event is on its way
- * through. May lead to new event being removed whilst the reported
- * event was the unescalated event. In typical use case this is not a
- * problem as userspace will say read half the buffer due to a 50%
- * full event which would make the correct 100% full incorrect anyway.
- */
- if (el->shared_pointer) {
- spin_lock(&el->shared_pointer->lock);
- (el->shared_pointer->ev_p) = NULL;
- spin_unlock(&el->shared_pointer->lock);
- }
kfree(el);

return len;
diff --git a/drivers/staging/iio/industrialio-ring.c b/drivers/staging/iio/industrialio-ring.c
index 1dfbc6e..466b9fa 100644
--- a/drivers/staging/iio/industrialio-ring.c
+++ b/drivers/staging/iio/industrialio-ring.c
@@ -27,28 +27,11 @@ int iio_push_ring_event(struct iio_ring_buffer *ring_buf,
s64 timestamp)
{
return __iio_push_event(&ring_buf->ev_int,
- event_code,
- timestamp,
- &ring_buf->shared_ev_pointer);
+ event_code,
+ timestamp);
}
EXPORT_SYMBOL(iio_push_ring_event);

-int iio_push_or_escallate_ring_event(struct iio_ring_buffer *ring_buf,
- int event_code,
- s64 timestamp)
-{
- if (ring_buf->shared_ev_pointer.ev_p)
- __iio_change_event(ring_buf->shared_ev_pointer.ev_p,
- event_code,
- timestamp);
- else
- return iio_push_ring_event(ring_buf,
- event_code,
- timestamp);
- return 0;
-}
-EXPORT_SYMBOL(iio_push_or_escallate_ring_event);
-
/**
* iio_ring_open() - chrdev file open for ring buffer access
*
@@ -228,8 +211,6 @@ void iio_ring_buffer_init(struct iio_ring_buffer *ring,
ring->indio_dev = dev_info;
ring->ev_int.private = ring;
ring->access_handler.private = ring;
- ring->shared_ev_pointer.ev_p = NULL;
- spin_lock_init(&ring->shared_ev_pointer.lock);
}
EXPORT_SYMBOL(iio_ring_buffer_init);

diff --git a/drivers/staging/iio/ring_generic.h b/drivers/staging/iio/ring_generic.h
index 6c7e073..320a11d 100644
--- a/drivers/staging/iio/ring_generic.h
+++ b/drivers/staging/iio/ring_generic.h
@@ -107,8 +107,6 @@ struct iio_ring_access_funcs {
* @scan_timestamp: [INTERN] does the scan mode include a timestamp
* @access_handler: [INTERN] chrdev access handling
* @ev_int: [INTERN] chrdev interface for the event chrdev
- * @shared_ev_pointer: [INTERN] the shared event pointer to allow escalation of
- * events
* @access: [DRIVER] ring access functions associated with the
* implementation.
* @preenable: [DRIVER] function to run prior to marking ring enabled
@@ -133,7 +131,6 @@ struct iio_ring_buffer {
bool scan_timestamp;
struct iio_handler access_handler;
struct iio_event_interface ev_int;
- struct iio_shared_ev_pointer shared_ev_pointer;
struct iio_ring_access_funcs access;
int (*preenable)(struct iio_dev *);
int (*postenable)(struct iio_dev *);
diff --git a/drivers/staging/iio/ring_sw.c b/drivers/staging/iio/ring_sw.c
index ea0015e..0004814 100644
--- a/drivers/staging/iio/ring_sw.c
+++ b/drivers/staging/iio/ring_sw.c
@@ -123,14 +123,6 @@ static int iio_store_to_sw_ring(struct iio_sw_ring_buffer *ring,
*/
if (change_test_ptr == ring->read_p)
ring->read_p = temp_ptr;
-
- spin_lock(&ring->buf.shared_ev_pointer.lock);
-
- ret = iio_push_or_escallate_ring_event(&ring->buf,
- IIO_EVENT_CODE_RING_100_FULL, timestamp);
- spin_unlock(&ring->buf.shared_ev_pointer.lock);
- if (ret)
- goto error_ret;
}
/* investigate if our event barrier has been passed */
/* There are definite 'issues' with this and chances of
@@ -140,15 +132,11 @@ static int iio_store_to_sw_ring(struct iio_sw_ring_buffer *ring,
if (ring->half_p == ring->data + ring->buf.length*ring->buf.bytes_per_datum)
ring->half_p = ring->data;
if (ring->half_p == ring->read_p) {
- spin_lock(&ring->buf.shared_ev_pointer.lock);
code = IIO_EVENT_CODE_RING_50_FULL;
ret = __iio_push_event(&ring->buf.ev_int,
code,
- timestamp,
- &ring->buf.shared_ev_pointer);
- spin_unlock(&ring->buf.shared_ev_pointer.lock);
+ timestamp);
}
-error_ret:
return ret;
}

--
1.7.3.4

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