[PATCH linux-next] s390:fix Coccinelle warnings

[PATCH linux-next] s390:fix Coccinelle warnings

[jing yangyang]

WARNING !A || A && B is equivalent to !A || B

This issue was detected with the help of Coccinelle.

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: jing yangyang <jing.yangyang@zte.com.cn>
---
 arch/s390/include/asm/scsw.h | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/arch/s390/include/asm/scsw.h b/arch/s390/include/asm/scsw.h
index a7c3ccf..754122d 100644
--- a/arch/s390/include/asm/scsw.h
+++ b/arch/s390/include/asm/scsw.h
@@ -691,9 +691,8 @@ static inline int scsw_tm_is_valid_pno(union scsw *scsw)
 {
 	return (scsw->tm.fctl != 0) &&
 	       (scsw->tm.stctl & SCSW_STCTL_STATUS_PEND) &&
-	       (!(scsw->tm.stctl & SCSW_STCTL_INTER_STATUS) ||
-		 ((scsw->tm.stctl & SCSW_STCTL_INTER_STATUS) &&
-		  (scsw->tm.actl & SCSW_ACTL_SUSPENDED)));
+		(!(scsw->tm.stctl & SCSW_STCTL_INTER_STATUS) ||
+		(scsw->tm.actl & SCSW_ACTL_SUSPENDED));
 }
 
 /**
-- 
1.8.3.1

Re: [PATCH linux-next] s390:fix Coccinelle warnings

[Heiko Carstens]

On Thu, Aug 19, 2021 at 07:51:59PM -0700, jing yangyang wrote:
> WARNING !A || A && B is equivalent to !A || B
> 
> This issue was detected with the help of Coccinelle.
> 
> Reported-by: Zeal Robot <zealci@zte.com.cn>
> Signed-off-by: jing yangyang <jing.yangyang@zte.com.cn>
> ---
>  arch/s390/include/asm/scsw.h | 5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/s390/include/asm/scsw.h b/arch/s390/include/asm/scsw.h
> index a7c3ccf..754122d 100644
> --- a/arch/s390/include/asm/scsw.h
> +++ b/arch/s390/include/asm/scsw.h
> @@ -691,9 +691,8 @@ static inline int scsw_tm_is_valid_pno(union scsw *scsw)
>  {
>  	return (scsw->tm.fctl != 0) &&
>  	       (scsw->tm.stctl & SCSW_STCTL_STATUS_PEND) &&
> -	       (!(scsw->tm.stctl & SCSW_STCTL_INTER_STATUS) ||
> -		 ((scsw->tm.stctl & SCSW_STCTL_INTER_STATUS) &&
> -		  (scsw->tm.actl & SCSW_ACTL_SUSPENDED)));
> +		(!(scsw->tm.stctl & SCSW_STCTL_INTER_STATUS) ||
> +		(scsw->tm.actl & SCSW_ACTL_SUSPENDED));

This turns something unreadable into something else which is
unreadable. It's up to Vineeth to decide what to do with this.

However I'd prefer if this would be changed into something readable,
maybe as addon patch, like e.g.:

static inline bool scsw_tm_is_valid_pno(union scsw *scsw)
{
	if (scsw->tm.fctl == 0)
		return false;
	if (!(scsw->tm.stctl & SCSW_STCTL_STATUS_PEND))
		return false;
	if (!(scsw->tm.stctl & SCSW_STCTL_INTER_STATUS))
		return false;
	if (scsw->tm.actl & SCSW_ACTL_SUSPENDED)
		return false;
	return true;
}

Chances are that the above is wrong... it's just to illustrate ;)

Re: [PATCH linux-next] s390:fix Coccinelle warnings

[Vineeth Vijayan]

I am a fan of Coccinelle fixes. But, here i think we need to do more 
work than just fixing it to
get rid of the warnings. I agree with Heiko. May be we should re-write 
this entire function and
make it readable.

Nack.


On 8/23/21 8:07 PM, Heiko Carstens wrote:
> On Thu, Aug 19, 2021 at 07:51:59PM -0700, jing yangyang wrote:
>> WARNING !A || A && B is equivalent to !A || B
>>
>> This issue was detected with the help of Coccinelle.
>>
>> Reported-by: Zeal Robot <zealci@zte.com.cn>
>> Signed-off-by: jing yangyang <jing.yangyang@zte.com.cn>
>> ---
>>   arch/s390/include/asm/scsw.h | 5 ++---
>>   1 file changed, 2 insertions(+), 3 deletions(-)
>>
>> diff --git a/arch/s390/include/asm/scsw.h b/arch/s390/include/asm/scsw.h
>> index a7c3ccf..754122d 100644
>> --- a/arch/s390/include/asm/scsw.h
>> +++ b/arch/s390/include/asm/scsw.h
>> @@ -691,9 +691,8 @@ static inline int scsw_tm_is_valid_pno(union scsw *scsw)
>>   {
>>   	return (scsw->tm.fctl != 0) &&
>>   	       (scsw->tm.stctl & SCSW_STCTL_STATUS_PEND) &&
>> -	       (!(scsw->tm.stctl & SCSW_STCTL_INTER_STATUS) ||
>> -		 ((scsw->tm.stctl & SCSW_STCTL_INTER_STATUS) &&
>> -		  (scsw->tm.actl & SCSW_ACTL_SUSPENDED)));
>> +		(!(scsw->tm.stctl & SCSW_STCTL_INTER_STATUS) ||
>> +		(scsw->tm.actl & SCSW_ACTL_SUSPENDED));
> This turns something unreadable into something else which is
> unreadable. It's up to Vineeth to decide what to do with this.
>
> However I'd prefer if this would be changed into something readable,
> maybe as addon patch, like e.g.:
>
> static inline bool scsw_tm_is_valid_pno(union scsw *scsw)
> {
> 	if (scsw->tm.fctl == 0)
> 		return false;
> 	if (!(scsw->tm.stctl & SCSW_STCTL_STATUS_PEND))
> 		return false;
> 	if (!(scsw->tm.stctl & SCSW_STCTL_INTER_STATUS))
> 		return false;
> 	if (scsw->tm.actl & SCSW_ACTL_SUSPENDED)
> 		return false;
> 	return true;
> }
>
> Chances are that the above is wrong... it's just to illustrate ;)