iio: adc: at91: signedness bug in at91_adc_get_trigger_value_by_name()

at91_adc_get_trigger_value_by_name() was returning -ENOMEM truncated to
a positive u8 and that doesn't work.  I've changed it to int and
refactored it to preserve the error code.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Tested-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Cc: Stable@vger.kernel.org

1 files changed, 8 insertions, 8 deletions

diff --git a/drivers/iio/adc/at91_adc.c b/drivers/iio/adc/at91_adc.c
index 89777ed9abd8..be0b2accf895 100644
--- a/drivers/iio/adc/at91_adc.c
+++ b/drivers/iio/adc/at91_adc.c
@@ -322,12 +322,11 @@ static int at91_adc_channel_init(struct iio_dev *idev)
         return idev->num_channels;
 }
 
-static u8 at91_adc_get_trigger_value_by_name(struct iio_dev *idev,
+static int at91_adc_get_trigger_value_by_name(struct iio_dev *idev,
                                              struct at91_adc_trigger *triggers,
                                              const char *trigger_name)
 {
         struct at91_adc_state *st = iio_priv(idev);
-        u8 value = 0;
         int i;
 
         for (i = 0; i < st->trigger_number; i++) {
@@ -340,15 +339,16 @@ static u8 at91_adc_get_trigger_value_by_name(struct iio_dev *idev,
                         return -ENOMEM;
 
                 if (strcmp(trigger_name, name) == 0) {
-                        value = triggers[i].value;
                         kfree(name);
-                        break;
+                        if (triggers[i].value == 0)
+                                return -EINVAL;
+                        return triggers[i].value;
                 }
 
                 kfree(name);
         }
 
-        return value;
+        return -EINVAL;
 }
 
 static int at91_adc_configure_trigger(struct iio_trigger *trig, bool state)
@@ -358,14 +358,14 @@ static int at91_adc_configure_trigger(struct iio_trigger *trig, bool state)
         struct iio_buffer *buffer = idev->buffer;
         struct at91_adc_reg_desc *reg = st->registers;
         u32 status = at91_adc_readl(st, reg->trigger_register);
-        u8 value;
+        int value;
         u8 bit;
 
         value = at91_adc_get_trigger_value_by_name(idev,
                                                    st->trigger_list,
                                                    idev->trig->name);
-        if (value == 0)
-                return -EINVAL;
+        if (value < 0)
+                return value;
 
         if (state) {
                 st->buffer = kmalloc(idev->scan_bytes, GFP_KERNEL);