Currently the fifo size is 512 elements. After a recent patch the size
of struct ir_raw_event is down to 8 bytes, so the fifo still consumes
4KB. In most cases a much smaller fifo is sufficient, e.g. nuvoton-cir
triggers event processing after 24 events latest. However the needed
fifo size may also depend on system performance.
Therefore make the fifo size a module parameter with the current value
of 512 being the default.
Signed-off-by: Heiner Kallweit <hkallweit1@xxxxxxxxx>
---
drivers/media/rc/rc-core-priv.h | 2 +-
drivers/media/rc/rc-ir-raw.c | 20 +++++++++++++++++---
2 files changed, 18 insertions(+), 4 deletions(-)
diff --git a/drivers/media/rc/rc-core-priv.h b/drivers/media/rc/rc-core-priv.h
index 585d5e5..ae6f81e 100644
--- a/drivers/media/rc/rc-core-priv.h
+++ b/drivers/media/rc/rc-core-priv.h
@@ -39,7 +39,7 @@ struct ir_raw_event_ctrl {
struct task_struct *thread;
spinlock_t lock;
/* fifo for the pulse/space durations */
- DECLARE_KFIFO(kfifo, struct ir_raw_event, MAX_IR_EVENT_SIZE);
+ DECLARE_KFIFO_PTR(kfifo, struct ir_raw_event);
ktime_t last_event; /* when last event occurred */
enum raw_event_type last_type; /* last event type */
struct rc_dev *dev; /* pointer to the parent rc_dev */
diff --git a/drivers/media/rc/rc-ir-raw.c b/drivers/media/rc/rc-ir-raw.c
index 144304c..620b036 100644
--- a/drivers/media/rc/rc-ir-raw.c
+++ b/drivers/media/rc/rc-ir-raw.c
@@ -18,6 +18,7 @@
#include <linux/kmod.h>
#include <linux/sched.h>
#include <linux/freezer.h>
+#include <linux/module.h>
#include "rc-core-priv.h"
/* Used to keep track of IR raw clients, protected by ir_raw_handler_lock */
@@ -28,6 +29,9 @@ static DEFINE_MUTEX(ir_raw_handler_lock);
static LIST_HEAD(ir_raw_handler_list);
static u64 available_protocols;
+/* module param */
+static unsigned int ir_raw_event_fifo_size = MAX_IR_EVENT_SIZE;
+
static int ir_raw_event_thread(void *data)
{
struct ir_raw_event ev;
@@ -262,7 +266,7 @@ int ir_raw_event_register(struct rc_dev *dev)
int rc;
struct ir_raw_handler *handler;
- if (!dev)
+ if (!dev || !ir_raw_event_fifo_size)
return -EINVAL;
dev->raw = kzalloc(sizeof(*dev->raw), GFP_KERNEL);
@@ -271,7 +275,10 @@ int ir_raw_event_register(struct rc_dev *dev)
dev->raw->dev = dev;
dev->change_protocol = change_protocol;
- INIT_KFIFO(dev->raw->kfifo);
+
+ rc = kfifo_alloc(&dev->raw->kfifo, ir_raw_event_fifo_size, GFP_KERNEL);
+ if (rc)
+ goto out;
spin_lock_init(&dev->raw->lock);
dev->raw->thread = kthread_run(ir_raw_event_thread, dev->raw,
@@ -279,7 +286,7 @@ int ir_raw_event_register(struct rc_dev *dev)
if (IS_ERR(dev->raw->thread)) {
rc = PTR_ERR(dev->raw->thread);
- goto out;
+ goto out_kfifo;
}
mutex_lock(&ir_raw_handler_lock);
@@ -291,6 +298,8 @@ int ir_raw_event_register(struct rc_dev *dev)
return 0;
+out_kfifo:
+ kfifo_free(&dev->raw->kfifo);
out:
kfree(dev->raw);
dev->raw = NULL;
@@ -313,6 +322,7 @@ void ir_raw_event_unregister(struct rc_dev *dev)
handler->raw_unregister(dev);
mutex_unlock(&ir_raw_handler_lock);
+ kfifo_free(&dev->raw->kfifo);
kfree(dev->raw);
dev->raw = NULL;
}
@@ -353,3 +363,7 @@ void ir_raw_handler_unregister(struct ir_raw_handler *ir_raw_handler)
mutex_unlock(&ir_raw_handler_lock);
}
EXPORT_SYMBOL(ir_raw_handler_unregister);
+
+module_param_named(fifo_size, ir_raw_event_fifo_size, uint, S_IRUGO);
+MODULE_PARM_DESC(fifo_size,
+ "raw event fifo size, will be rounded up to next power of 2");
--
2.7.3
--
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