[media] lirc_dev: allow bufferless driver registration
Transmitters don't necessarily need to have a FIFO managed buffer
for their transfers.
When registering the driver, before allocating the buffer, check
whether the device is a transmitter or receiver. Allocate the
buffer only for receivers.
Signed-off-by: Andi Shyti <andi.shyti@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
diff --git a/drivers/media/rc/lirc_dev.c b/drivers/media/rc/lirc_dev.c
index 5716978..154e553 100644
--- a/drivers/media/rc/lirc_dev.c
+++ b/drivers/media/rc/lirc_dev.c
@@ -205,12 +205,14 @@
static int lirc_allocate_buffer(struct irctl *ir)
{
- int err;
+ int err = 0;
int bytes_in_key;
unsigned int chunk_size;
unsigned int buffer_size;
struct lirc_driver *d = &ir->d;
+ mutex_lock(&lirc_dev_lock);
+
bytes_in_key = BITS_TO_LONGS(d->code_length) +
(d->code_length % 8 ? 1 : 0);
buffer_size = d->buffer_size ? d->buffer_size : BUFLEN / bytes_in_key;
@@ -220,21 +222,26 @@
ir->buf = d->rbuf;
} else {
ir->buf = kmalloc(sizeof(struct lirc_buffer), GFP_KERNEL);
- if (!ir->buf)
- return -ENOMEM;
+ if (!ir->buf) {
+ err = -ENOMEM;
+ goto out;
+ }
err = lirc_buffer_init(ir->buf, chunk_size, buffer_size);
if (err) {
kfree(ir->buf);
- return err;
+ goto out;
}
}
ir->chunk_size = ir->buf->chunk_size;
- return 0;
+out:
+ mutex_unlock(&lirc_dev_lock);
+
+ return err;
}
-int lirc_register_driver(struct lirc_driver *d)
+static int lirc_allocate_driver(struct lirc_driver *d)
{
struct irctl *ir;
int minor;
@@ -342,10 +349,6 @@
/* some safety check 8-) */
d->name[sizeof(d->name)-1] = '\0';
- err = lirc_allocate_buffer(ir);
- if (err)
- goto out_lock;
-
if (d->features == 0)
d->features = LIRC_CAN_REC_LIRCCODE;
@@ -385,6 +388,23 @@
out:
return err;
}
+
+int lirc_register_driver(struct lirc_driver *d)
+{
+ int minor, err = 0;
+
+ minor = lirc_allocate_driver(d);
+ if (minor < 0)
+ return minor;
+
+ if (LIRC_CAN_REC(d->features)) {
+ err = lirc_allocate_buffer(irctls[minor]);
+ if (err)
+ lirc_unregister_driver(minor);
+ }
+
+ return err ? err : minor;
+}
EXPORT_SYMBOL(lirc_register_driver);
int lirc_unregister_driver(int minor)