* [PATCH] iio: imu: adis16400: Fix sign extension
@ 2015-01-22 23:34 Rasmus Villemoes
2015-01-23 8:56 ` Lars-Peter Clausen
0 siblings, 1 reply; 3+ messages in thread
From: Rasmus Villemoes @ 2015-01-22 23:34 UTC (permalink / raw)
To: Lars-Peter Clausen, Michael Hennerich, Jonathan Cameron,
Hartmut Knaack, Peter Meerwald
Cc: Rasmus Villemoes, linux-iio, linux-kernel
The intention is obviously to sign-extend a 12 bit quantity. But
because of C's promotion rules, the assignment is equivalent to "val16
&= 0xfff;". Use the proper API for this.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
---
drivers/iio/imu/adis16400_core.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/iio/imu/adis16400_core.c b/drivers/iio/imu/adis16400_core.c
index b70873de04ea..fa795dcd5f75 100644
--- a/drivers/iio/imu/adis16400_core.c
+++ b/drivers/iio/imu/adis16400_core.c
@@ -26,6 +26,7 @@
#include <linux/list.h>
#include <linux/module.h>
#include <linux/debugfs.h>
+#include <linux/bitops.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
@@ -414,7 +415,7 @@ static int adis16400_read_raw(struct iio_dev *indio_dev,
mutex_unlock(&indio_dev->mlock);
if (ret)
return ret;
- val16 = ((val16 & 0xFFF) << 4) >> 4;
+ val16 = sign_extend32(val16, 11);
*val = val16;
return IIO_VAL_INT;
case IIO_CHAN_INFO_OFFSET:
--
2.1.3
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] iio: imu: adis16400: Fix sign extension
2015-01-22 23:34 [PATCH] iio: imu: adis16400: Fix sign extension Rasmus Villemoes
@ 2015-01-23 8:56 ` Lars-Peter Clausen
2015-01-26 21:07 ` Jonathan Cameron
0 siblings, 1 reply; 3+ messages in thread
From: Lars-Peter Clausen @ 2015-01-23 8:56 UTC (permalink / raw)
To: Rasmus Villemoes, Michael Hennerich, Jonathan Cameron,
Hartmut Knaack, Peter Meerwald
Cc: linux-iio, linux-kernel
On 01/23/2015 12:34 AM, Rasmus Villemoes wrote:
> The intention is obviously to sign-extend a 12 bit quantity. But
> because of C's promotion rules, the assignment is equivalent to "val16
> &= 0xfff;". Use the proper API for this.
>
> Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] iio: imu: adis16400: Fix sign extension
2015-01-23 8:56 ` Lars-Peter Clausen
@ 2015-01-26 21:07 ` Jonathan Cameron
0 siblings, 0 replies; 3+ messages in thread
From: Jonathan Cameron @ 2015-01-26 21:07 UTC (permalink / raw)
To: Lars-Peter Clausen, Rasmus Villemoes, Michael Hennerich,
Hartmut Knaack, Peter Meerwald
Cc: linux-iio, linux-kernel
On 23/01/15 08:56, Lars-Peter Clausen wrote:
> On 01/23/2015 12:34 AM, Rasmus Villemoes wrote:
>> The intention is obviously to sign-extend a 12 bit quantity. But
>> because of C's promotion rules, the assignment is equivalent to "val16
>> &= 0xfff;". Use the proper API for this.
>>
>> Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
>
> Acked-by: Lars-Peter Clausen <lars@metafoo.de>
>
Applied to the fixes-togreg branch of iio.git and cc'd to stable.
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2015-01-26 21:07 UTC | newest]
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2015-01-22 23:34 [PATCH] iio: imu: adis16400: Fix sign extension Rasmus Villemoes
2015-01-23 8:56 ` Lars-Peter Clausen
2015-01-26 21:07 ` Jonathan Cameron
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