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authorLars-Peter Clausen <lars@metafoo.de>2013-03-26 18:43:00 +0000
committerJonathan Cameron <jic23@kernel.org>2013-03-29 09:16:47 +0000
commitd8dca33027c1fda3318fe8af85456b801ef88e1e (patch)
tree470c0d2b64075ccb2cf57fd1e8cfd16e69f28ced
parentd00698df2180ecd78b2892856b310dfedd5f6fe7 (diff)
staging:iio:ad799x: Preallocate sample buffer
Avoid allocating and freeing the sample buffer for each transfer. Instead allocate it once when we start sampling. Also pre-compute the number of bytes we need to transfer in the same way. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
-rw-r--r--drivers/staging/iio/adc/ad799x.h3
-rw-r--r--drivers/staging/iio/adc/ad799x_core.c8
-rw-r--r--drivers/staging/iio/adc/ad799x_ring.c16
3 files changed, 15 insertions, 12 deletions
diff --git a/drivers/staging/iio/adc/ad799x.h b/drivers/staging/iio/adc/ad799x.h
index 82e83bbb342b..b51680c1c331 100644
--- a/drivers/staging/iio/adc/ad799x.h
+++ b/drivers/staging/iio/adc/ad799x.h
@@ -106,6 +106,9 @@ struct ad799x_state {
u16 int_vref_mv;
unsigned id;
u16 config;
+
+ u8 *rx_buf;
+ unsigned int transfer_size;
};
/*
diff --git a/drivers/staging/iio/adc/ad799x_core.c b/drivers/staging/iio/adc/ad799x_core.c
index b7510557d064..8dc97b36e05a 100644
--- a/drivers/staging/iio/adc/ad799x_core.c
+++ b/drivers/staging/iio/adc/ad799x_core.c
@@ -104,6 +104,13 @@ static int ad7997_8_update_scan_mode(struct iio_dev *indio_dev,
{
struct ad799x_state *st = iio_priv(indio_dev);
+ kfree(st->rx_buf);
+ st->rx_buf = kmalloc(indio_dev->scan_bytes, GFP_KERNEL);
+ if (!st->rx_buf)
+ return -ENOMEM;
+
+ st->transfer_size = bitmap_weight(scan_mask, indio_dev->masklength) * 2;
+
switch (st->id) {
case ad7997:
case ad7998:
@@ -665,6 +672,7 @@ static int ad799x_remove(struct i2c_client *client)
regulator_disable(st->reg);
regulator_put(st->reg);
}
+ kfree(st->rx_buf);
iio_device_free(indio_dev);
return 0;
diff --git a/drivers/staging/iio/adc/ad799x_ring.c b/drivers/staging/iio/adc/ad799x_ring.c
index 2c5f38475a8e..c2ebae12ee19 100644
--- a/drivers/staging/iio/adc/ad799x_ring.c
+++ b/drivers/staging/iio/adc/ad799x_ring.c
@@ -36,14 +36,9 @@ static irqreturn_t ad799x_trigger_handler(int irq, void *p)
struct iio_dev *indio_dev = pf->indio_dev;
struct ad799x_state *st = iio_priv(indio_dev);
s64 time_ns;
- __u8 *rxbuf;
int b_sent;
u8 cmd;
- rxbuf = kmalloc(indio_dev->scan_bytes, GFP_KERNEL);
- if (rxbuf == NULL)
- goto out;
-
switch (st->id) {
case ad7991:
case ad7995:
@@ -66,20 +61,17 @@ static irqreturn_t ad799x_trigger_handler(int irq, void *p)
}
b_sent = i2c_smbus_read_i2c_block_data(st->client,
- cmd, bitmap_weight(indio_dev->active_scan_mask,
- indio_dev->masklength) * 2, rxbuf);
+ cmd, st->transfer_size, st->rx_buf);
if (b_sent < 0)
- goto done;
+ goto out;
time_ns = iio_get_time_ns();
if (indio_dev->scan_timestamp)
- memcpy(rxbuf + indio_dev->scan_bytes - sizeof(s64),
+ memcpy(st->rx_buf + indio_dev->scan_bytes - sizeof(s64),
&time_ns, sizeof(time_ns));
- iio_push_to_buffers(indio_dev, rxbuf);
-done:
- kfree(rxbuf);
+ iio_push_to_buffers(indio_dev, st->rx_buf);
out:
iio_trigger_notify_done(indio_dev->trig);