* [PATCH v2 1/1] iio: core: Fix fractional format generation
@ 2019-08-22 6:06 Alexander Stein
2019-11-07 13:54 ` Alexander Stein
0 siblings, 1 reply; 3+ messages in thread
From: Alexander Stein @ 2019-08-22 6:06 UTC (permalink / raw)
To: Jonathan Cameron, Hartmut Knaack, Lars-Peter Clausen,
Peter Meerwald-Stadler
Cc: Alexander Stein, linux-iio, linux-kernel
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;
--
2.23.0
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH v2 1/1] iio: core: Fix fractional format generation
2019-08-22 6:06 [PATCH v2 1/1] iio: core: Fix fractional format generation Alexander Stein
@ 2019-11-07 13:54 ` Alexander Stein
2019-11-09 11:55 ` Jonathan Cameron
0 siblings, 1 reply; 3+ messages in thread
From: Alexander Stein @ 2019-11-07 13:54 UTC (permalink / raw)
To: Jonathan Cameron
Cc: Hartmut Knaack, Lars-Peter Clausen, Peter Meerwald-Stadler,
linux-iio, linux-kernel
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
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^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH v2 1/1] iio: core: Fix fractional format generation
2019-11-07 13:54 ` Alexander Stein
@ 2019-11-09 11:55 ` Jonathan Cameron
0 siblings, 0 replies; 3+ messages in thread
From: Jonathan Cameron @ 2019-11-09 11:55 UTC (permalink / raw)
To: Alexander Stein
Cc: Hartmut Knaack, Lars-Peter Clausen, Peter Meerwald-Stadler,
linux-iio, linux-kernel
On Thu, 07 Nov 2019 14:54:52 +0100
Alexander Stein <alexander.stein@systec-electronic.com> wrote:
> 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>
Apologies. I'd missed this v2 entirely for some reason.
It looks correct to me, but as Lars had inputs on v1...
Lars, could you take a quick look at this v2 and give an ack if
you are happy with it.
Thanks,
Jonathan
> > ---
> > 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;
> >
>
>
^ permalink raw reply [flat|nested] 3+ messages in thread
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2019-08-22 6:06 [PATCH v2 1/1] iio: core: Fix fractional format generation Alexander Stein
2019-11-07 13:54 ` Alexander Stein
2019-11-09 11:55 ` Jonathan Cameron
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