From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx07-00178001.pphosted.com ([62.209.51.94]:16384 "EHLO mx07-00178001.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751781AbcC1Dmm (ORCPT ); Sun, 27 Mar 2016 23:42:42 -0400 Date: Mon, 28 Mar 2016 11:42:33 +0800 From: Denis Ciocca To: Linus Walleij CC: Jonathan Cameron , "linux-iio@vger.kernel.org" , Giuseppe BARBA Subject: Re: [PATCH 1/4] iio: st_sensors: simplify buffer address handling Message-ID: <20160328034233.GA5682@beicxl1122> References: <1458825486-17188-1-git-send-email-linus.walleij@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" In-Reply-To: <1458825486-17188-1-git-send-email-linus.walleij@linaro.org> Sender: linux-iio-owner@vger.kernel.org List-Id: linux-iio@vger.kernel.org Hi Linus, it makes sense to me. Thanks Acked-by: Denis Ciocca On |24 Mar 16 @ 14:18|, Linus Walleij wrote: > The driver goes to some length to dynamically allocate an array > to hold the channel addresses. However no ST sensor has more than > three channels (x, y, z at most). Instead of kmalloc():ing and > kfree():in the address array, just use a fixed array of three > elements. > > Cc: Giuseppe Barba > Cc: Denis Ciocca > Signed-off-by: Linus Walleij > --- > drivers/iio/common/st_sensors/st_sensors_buffer.c | 28 ++++++----------------- > 1 file changed, 7 insertions(+), 21 deletions(-) > > diff --git a/drivers/iio/common/st_sensors/st_sensors_buffer.c b/drivers/iio/common/st_sensors/st_sensors_buffer.c > index e18bc6782256..73764961feac 100644 > --- a/drivers/iio/common/st_sensors/st_sensors_buffer.c > +++ b/drivers/iio/common/st_sensors/st_sensors_buffer.c > @@ -24,19 +24,13 @@ > > int st_sensors_get_buffer_element(struct iio_dev *indio_dev, u8 *buf) > { > - u8 *addr; > + u8 addr[3]; /* no ST sensor has more than 3 channels */ > int i, n = 0, len; > struct st_sensor_data *sdata = iio_priv(indio_dev); > unsigned int num_data_channels = sdata->num_data_channels; > unsigned int byte_for_channel = > indio_dev->channels[0].scan_type.storagebits >> 3; > > - addr = kmalloc(num_data_channels, GFP_KERNEL); > - if (!addr) { > - len = -ENOMEM; > - goto st_sensors_get_buffer_element_error; > - } > - > for (i = 0; i < num_data_channels; i++) { > if (test_bit(i, indio_dev->active_scan_mask)) { > addr[n] = indio_dev->channels[i].address; > @@ -57,10 +51,8 @@ int st_sensors_get_buffer_element(struct iio_dev *indio_dev, u8 *buf) > u8 *rx_array; > rx_array = kmalloc(byte_for_channel * num_data_channels, > GFP_KERNEL); > - if (!rx_array) { > - len = -ENOMEM; > - goto st_sensors_free_memory; > - } > + if (!rx_array) > + return -ENOMEM; > > len = sdata->tf->read_multiple_byte(&sdata->tb, > sdata->dev, addr[0], > @@ -68,7 +60,7 @@ int st_sensors_get_buffer_element(struct iio_dev *indio_dev, u8 *buf) > rx_array, sdata->multiread_bit); > if (len < 0) { > kfree(rx_array); > - goto st_sensors_free_memory; > + return len; > } > > for (i = 0; i < n * byte_for_channel; i++) { > @@ -87,17 +79,11 @@ int st_sensors_get_buffer_element(struct iio_dev *indio_dev, u8 *buf) > buf, sdata->multiread_bit); > break; > default: > - len = -EINVAL; > - goto st_sensors_free_memory; > - } > - if (len != byte_for_channel * n) { > - len = -EIO; > - goto st_sensors_free_memory; > + return -EINVAL; > } > + if (len != byte_for_channel * n) > + return -EIO; > > -st_sensors_free_memory: > - kfree(addr); > -st_sensors_get_buffer_element_error: > return len; > } > EXPORT_SYMBOL(st_sensors_get_buffer_element); > -- > 2.4.3 >