Re: [PATCH 1/4] iio: st_sensors: simplify buffer address handling

[Jonathan Cameron <jic23@kernel.org>]

On 28/03/16 04:42, Denis Ciocca wrote:
> Hi Linus,
> 
> it makes sense to me. Thanks
> 
> Acked-by: Denis Ciocca <denis.ciocca@st.com>
Applied to the togreg branch of iio.git.

Denis, any comments on the rest of the series?
> 
> 
> 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 <giuseppe.barba@st.com>
>> Cc: Denis Ciocca <denis.ciocca@st.com>
>> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
>> ---
>>  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
>>
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