2022-10-28 06:42:07

by jovial umwari

Subject: [PATCH] Remove Unnecessary typecast of c90 int constant

According to Linux kernel coding style.

Reported by checkpatch:
WARNING: Unnecessary typecast of c90 int constant - '(int)2.412e8' could be '2.412e8'
WARNING: Unnecessary typecast of c90 int constant - '(int)2.487e8' could be '2.487e8'

Signed-off-by: UMWARI JOVIAL <[email protected]>
---
drivers/staging/rtl8192e/rtllib_softmac_wx.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/rtl8192e/rtllib_softmac_wx.c b/drivers/staging/rtl8192e/rtllib_softmac_wx.c
index fdf867a5dd7a..4fc4fb25d8d6 100644
--- a/drivers/staging/rtl8192e/rtllib_softmac_wx.c
+++ b/drivers/staging/rtl8192e/rtllib_softmac_wx.c
@@ -41,8 +41,8 @@ int rtllib_wx_set_freq(struct rtllib_device *ieee, struct iw_request_info *a,

/* if setting by freq convert to channel */
if (fwrq->e == 1) {
- if ((fwrq->m >= (int)2.412e8 &&
- fwrq->m <= (int)2.487e8)) {
+ if ((fwrq->m >= 2.412e8 &&
+ fwrq->m <= 2.487e8)) {
int f = fwrq->m / 100000;
int c = 0;

--
2.25.1

2022-10-28 07:38:13

by Julia Lawall

Subject: Re: [PATCH] Remove Unnecessary typecast of c90 int constant

On Fri, 28 Oct 2022, UMWARI JOVIAL wrote:

> According to Linux kernel coding style.
>
> Reported by checkpatch:
> WARNING: Unnecessary typecast of c90 int constant - '(int)2.412e8' could be '2.412e8'
> WARNING: Unnecessary typecast of c90 int constant - '(int)2.487e8' could be '2.487e8'

It's not ideal to just include the checkpatch messges verbatim in your log
message. It woudl be better to say what you are doing and why, in
complete sentences ("According to the Linux coding style" is not a
complete sentence).

I also suspect that the checkpatch message is wrong. Floating point
numbers cannot be used in the kernel, and the case of the constant ensures
that the value will be converted to an integer at compile time.

julia

>
> Signed-off-by: UMWARI JOVIAL <[email protected]>
> ---
> drivers/staging/rtl8192e/rtllib_softmac_wx.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/staging/rtl8192e/rtllib_softmac_wx.c b/drivers/staging/rtl8192e/rtllib_softmac_wx.c
> index fdf867a5dd7a..4fc4fb25d8d6 100644
> --- a/drivers/staging/rtl8192e/rtllib_softmac_wx.c
> +++ b/drivers/staging/rtl8192e/rtllib_softmac_wx.c
> @@ -41,8 +41,8 @@ int rtllib_wx_set_freq(struct rtllib_device *ieee, struct iw_request_info *a,
>
> /* if setting by freq convert to channel */
> if (fwrq->e == 1) {
> - if ((fwrq->m >= (int)2.412e8 &&
> - fwrq->m <= (int)2.487e8)) {
> + if ((fwrq->m >= 2.412e8 &&
> + fwrq->m <= 2.487e8)) {
> int f = fwrq->m / 100000;
> int c = 0;
>
> --
> 2.25.1
>
>
>

2022-10-28 08:03:55

by jovial umwari

Subject: Re: [PATCH] Remove Unnecessary typecast of c90 int constant

let me again look in deep into it and see why
Thank you for the comment

On Fri, 28 Oct 2022 at 10:22, Julia Lawall <[email protected]> wrote:
>
>
>
> On Fri, 28 Oct 2022, UMWARI JOVIAL wrote:
>
> > According to Linux kernel coding style.
> >
> > Reported by checkpatch:
> > WARNING: Unnecessary typecast of c90 int constant - '(int)2.412e8' could be '2.412e8'
> > WARNING: Unnecessary typecast of c90 int constant - '(int)2.487e8' could be '2.487e8'
>
> It's not ideal to just include the checkpatch messges verbatim in your log
> message. It woudl be better to say what you are doing and why, in
> complete sentences ("According to the Linux coding style" is not a
> complete sentence).
>
> I also suspect that the checkpatch message is wrong. Floating point
> numbers cannot be used in the kernel, and the case of the constant ensures
> that the value will be converted to an integer at compile time.
>
> julia
>
> >
> > Signed-off-by: UMWARI JOVIAL <[email protected]>
> > ---
> > drivers/staging/rtl8192e/rtllib_softmac_wx.c | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/staging/rtl8192e/rtllib_softmac_wx.c b/drivers/staging/rtl8192e/rtllib_softmac_wx.c
> > index fdf867a5dd7a..4fc4fb25d8d6 100644
> > --- a/drivers/staging/rtl8192e/rtllib_softmac_wx.c
> > +++ b/drivers/staging/rtl8192e/rtllib_softmac_wx.c
> > @@ -41,8 +41,8 @@ int rtllib_wx_set_freq(struct rtllib_device *ieee, struct iw_request_info *a,
> >
> > /* if setting by freq convert to channel */
> > if (fwrq->e == 1) {
> > - if ((fwrq->m >= (int)2.412e8 &&
> > - fwrq->m <= (int)2.487e8)) {
> > + if ((fwrq->m >= 2.412e8 &&
> > + fwrq->m <= 2.487e8)) {
> > int f = fwrq->m / 100000;
> > int c = 0;
> >
> > --
> > 2.25.1
> >
> >
> >

2022-10-29 11:29:10

by David Laight

Subject: RE: [PATCH] Remove Unnecessary typecast of c90 int constant

From: Julia Lawall
> Sent: 28 October 2022 08:23
>
> On Fri, 28 Oct 2022, UMWARI JOVIAL wrote:
>
> > According to Linux kernel coding style.
> >
> > Reported by checkpatch:
> > WARNING: Unnecessary typecast of c90 int constant - '(int)2.412e8' could be '2.412e8'
> > WARNING: Unnecessary typecast of c90 int constant - '(int)2.487e8' could be '2.487e8'
>
> It's not ideal to just include the checkpatch messges verbatim in your log
> message. It woudl be better to say what you are doing and why, in
> complete sentences ("According to the Linux coding style" is not a
> complete sentence).
>
> I also suspect that the checkpatch message is wrong. Floating point
> numbers cannot be used in the kernel, and the case of the constant ensures
> that the value will be converted to an integer at compile time.

Much better to just use 241200000u (or 241200u * 1000 for readability).

David

>
> julia
>
> >
> > Signed-off-by: UMWARI JOVIAL <[email protected]>
> > ---
> > drivers/staging/rtl8192e/rtllib_softmac_wx.c | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/staging/rtl8192e/rtllib_softmac_wx.c
> b/drivers/staging/rtl8192e/rtllib_softmac_wx.c
> > index fdf867a5dd7a..4fc4fb25d8d6 100644
> > --- a/drivers/staging/rtl8192e/rtllib_softmac_wx.c
> > +++ b/drivers/staging/rtl8192e/rtllib_softmac_wx.c
> > @@ -41,8 +41,8 @@ int rtllib_wx_set_freq(struct rtllib_device *ieee, struct iw_request_info *a,
> >
> > /* if setting by freq convert to channel */
> > if (fwrq->e == 1) {
> > - if ((fwrq->m >= (int)2.412e8 &&
> > - fwrq->m <= (int)2.487e8)) {
> > + if ((fwrq->m >= 2.412e8 &&
> > + fwrq->m <= 2.487e8)) {
> > int f = fwrq->m / 100000;
> > int c = 0;
> >
> > --
> > 2.25.1
> >
> >
> >

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)

2022-10-29 15:00:19

by Joe Perches

Subject: Re: [PATCH] Remove Unnecessary typecast of c90 int constant

On Fri, 2022-10-28 at 09:22 +0200, Julia Lawall wrote:
>
> On Fri, 28 Oct 2022, UMWARI JOVIAL wrote:
>
> > According to Linux kernel coding style.
> >
> > Reported by checkpatch:
> > WARNING: Unnecessary typecast of c90 int constant - '(int)2.412e8' could be '2.412e8'
> > WARNING: Unnecessary typecast of c90 int constant - '(int)2.487e8' could be '2.487e8'
>
> It's not ideal to just include the checkpatch messges verbatim in your log
> message. It woudl be better to say what you are doing and why, in
> complete sentences ("According to the Linux coding style" is not a
> complete sentence).
>
> I also suspect that the checkpatch message is wrong. Floating point
> numbers cannot be used in the kernel, and the case of the constant ensures
> that the value will be converted to an integer at compile time.

Yes, it's a checkpatch defect.

checkpatch should have this:
---
diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 4e187202e77a6..9958a774efaf1 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -6758,7 +6759,8 @@ sub process {
}

# check for cast of C90 native int or longer types constants
- if ($line =~ /(\(\s*$C90_int_types\s*\)\s*)($Constant)\b/) {
+ if ($line =~ /(\(\s*$C90_int_types\s*\)\s*)($Constant)\b/ &&
+ $2 !~ /^$Float$/) {
my $cast = $1;
my $const = $2;
my $suffix = "";