lkml.org 
[lkml]   [2019]   [Nov]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: [PATCH v2 1/1] iio: core: Fix fractional format generation
Date
Gentle ping

On Thursday, August 22, 2019, 8:06:07 AM CET Alexander Stein wrote:
> In case the result is -0.3252 tmp0 is 0 after the div_s64_rem, so tmp0 is
> non-negative which results in an output of 0.3252.
> Fix this by explicitly handling the negative sign ourselves.
>
> Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com>
> ---
> Changes in v2:
> * Support vals[0] >= and vals[1] < 0 in IIO_VAL_FRACTIONAL
> * Note: IIO_VAL_FRACTIONAL is untested, as I lack hardware
> * Note2: Currently IIO_VAL_FRACTIONAL is only called with vals[1] from
> in-kernel drivers AFAICS
>
> drivers/iio/industrialio-core.c | 11 +++++++++--
> 1 file changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
> index 245b5844028d..247338142c87 100644
> --- a/drivers/iio/industrialio-core.c
> +++ b/drivers/iio/industrialio-core.c
> @@ -568,6 +568,7 @@ static ssize_t __iio_format_value(char *buf, size_t len, unsigned int type,
> {
> unsigned long long tmp;
> int tmp0, tmp1;
> + char *sign;
> bool scale_db = false;
>
> switch (type) {
> @@ -593,11 +594,17 @@ static ssize_t __iio_format_value(char *buf, size_t len, unsigned int type,
> tmp = div_s64((s64)vals[0] * 1000000000LL, vals[1]);
> tmp1 = vals[1];
> tmp0 = (int)div_s64_rem(tmp, 1000000000, &tmp1);
> - return snprintf(buf, len, "%d.%09u", tmp0, abs(tmp1));
> + if (vals[1] < 0) {
> + sign = vals[0] >= 0 ? "-" : "";
> + } else {
> + sign = vals[0] < 0 ? "-" : "";
> + }
> + return snprintf(buf, len, "%s%u.%09u", sign, abs(tmp0), abs(tmp1));
> case IIO_VAL_FRACTIONAL_LOG2:
> + sign = vals[0] < 0 ? "-" : "";
> tmp = shift_right((s64)vals[0] * 1000000000LL, vals[1]);
> tmp0 = (int)div_s64_rem(tmp, 1000000000LL, &tmp1);
> - return snprintf(buf, len, "%d.%09u", tmp0, abs(tmp1));
> + return snprintf(buf, len, "%s%u.%09u", sign, abs(tmp0), abs(tmp1));
> case IIO_VAL_INT_MULTIPLE:
> {
> int i;
>


--
Dipl-Inf. Alexander Stein

SYS TEC electronic AG
Am Windrad 2
08468 Heinsdorfergrund
Germany
Tel: +49-3765-38600-0, Fax: +49-3765-38600-4100
Email : alexander.stein@systec-electronic.com
Internet: http://www.systec-electronic.com

Board of Directors: Dipl.-Ing. Ronald Sieber, Dipl.-Ing. Dirk Bause
Chairman of the Supervisory Board: Dipl.-Phys. Siegmar Schmidt
Commercial registry: Amtsgericht Chemnitz, HRB 32220; USt.-Id Nr.
DE150534010

--------------------------------------------------------------------------

Diese E-Mail enthält vertrauliche und/oder rechtlich geschützte
Informationen.

Wenn Sie nicht der richtige Adressat sind oder diese E-Mail irrtümlich
erhalten haben, informieren Sie bitte sofort den Absender und vernichten
Sie diese Mail.

Das unerlaubte Kopieren sowie die unbefugte Weitergabe dieser Mail sind
nicht gestattet.

--------------------------------------------------------------------------

This e-mail may contain confidential and/or privileged information.

If you are not the intended recipient (or have received this e-mail in
error) please notify the sender immediately and destroy this e-mail.

Any unauthorized copying, disclosure or distribution of the material in
this e-mail is strictly forbidden.

--------------------------------------------------------------------------


\
 
 \ /
  Last update: 2019-11-07 15:05    [W:0.053 / U:39.364 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site