On Sat, 14 Dec 2024 20:14:19 +0100
Vasileios Amoiridis <vassilisamir@xxxxxxxxx> wrote:
Patch needs a new title. I'll fix it up.
Use a small fixed size buffer to replace dynamic allocation
with that, applied.
Thanks,
> Drop the recurrent allocation of the data buffer from the trigger
> handler and put it in the iio_priv(). This way, the maximum amount of
> channels is always allocated in favor of simpler code and drop
> of usage of the internal private variable "scan_timestamp" of the
> struct iio_dev.
>
> Signed-off-by: Vasileios Amoiridis <vassilisamir@xxxxxxxxx>
> ---
> drivers/iio/adc/max1363.c | 30 +++++++++---------------------
> 1 file changed, 9 insertions(+), 21 deletions(-)
>
> diff --git a/drivers/iio/adc/max1363.c b/drivers/iio/adc/max1363.c
> index 9a0baea08ab6..e8d731bc34e0 100644
> --- a/drivers/iio/adc/max1363.c
> +++ b/drivers/iio/adc/max1363.c
> @@ -161,6 +161,7 @@ struct max1363_chip_info {
> * @vref_uv: Actual (external or internal) reference voltage
> * @send: function used to send data to the chip
> * @recv: function used to receive data from the chip
> + * @data: buffer to store channel data and timestamp
> */
> struct max1363_state {
> struct i2c_client *client;
> @@ -186,6 +187,10 @@ struct max1363_state {
> const char *buf, int count);
> int (*recv)(const struct i2c_client *client,
> char *buf, int count);
> + struct {
> + u8 buf[MAX1363_MAX_CHANNELS * 2];
> + aligned_s64 ts;
> + } data;
> };
>
> #define MAX1363_MODE_SINGLE(_num, _mask) { \
> @@ -1462,22 +1467,10 @@ static irqreturn_t max1363_trigger_handler(int irq, void *p)
> struct iio_poll_func *pf = p;
> struct iio_dev *indio_dev = pf->indio_dev;
> struct max1363_state *st = iio_priv(indio_dev);
> - __u8 *rxbuf;
> int b_sent;
> - size_t d_size;
> unsigned long numvals = bitmap_weight(st->current_mode->modemask,
> MAX1363_MAX_CHANNELS);
>
> - /* Ensure the timestamp is 8 byte aligned */
> - if (st->chip_info->bits != 8)
> - d_size = numvals*2;
> - else
> - d_size = numvals;
> - if (indio_dev->scan_timestamp) {
> - d_size += sizeof(s64);
> - if (d_size % sizeof(s64))
> - d_size += sizeof(s64) - (d_size % sizeof(s64));
> - }
> /* Monitor mode prevents reading. Whilst not currently implemented
> * might as well have this test in here in the meantime as it does
> * no harm.
> @@ -1485,21 +1478,16 @@ static irqreturn_t max1363_trigger_handler(int irq, void *p)
> if (numvals == 0)
> goto done;
>
> - rxbuf = kmalloc(d_size, GFP_KERNEL);
> - if (rxbuf == NULL)
> - goto done;
> if (st->chip_info->bits != 8)
> - b_sent = st->recv(st->client, rxbuf, numvals * 2);
> + b_sent = st->recv(st->client, st->data.buf, numvals * 2);
> else
> - b_sent = st->recv(st->client, rxbuf, numvals);
> + b_sent = st->recv(st->client, st->data.buf, numvals);
> if (b_sent < 0)
> - goto done_free;
> + goto done;
>
> - iio_push_to_buffers_with_timestamp(indio_dev, rxbuf,
> + iio_push_to_buffers_with_timestamp(indio_dev, &st->data,
> iio_get_time_ns(indio_dev));
>
> -done_free:
> - kfree(rxbuf);
> done:
> iio_trigger_notify_done(indio_dev->trig);
>
