[PATCH] staging: gpib: Remove unused value

[PATCH] staging: gpib: Remove unused value

[Everest K.C.]

The variable `complement_count` is assigned a value which is again
overwritten in the next statement.
Fix this by removing the first value assigning statement

This issue was reported by Coverity Scan.
Report:
CID 1600790: (#1 of 1): Unused value (UNUSED_VALUE)
assigned_value: Assigning value from length to complement_count here,
but that stored value is overwritten before it can be used.

Fixes: 4e127de14fa7 ("staging: gpib: Add National Instruments USB GPIB driver")
Signed-off-by: Everest K.C. <everestkc@everestkc.com.np>
---
 drivers/staging/gpib/ni_usb/ni_usb_gpib.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/staging/gpib/ni_usb/ni_usb_gpib.c b/drivers/staging/gpib/ni_usb/ni_usb_gpib.c
index 1da263676f2a..e19e18892468 100644
--- a/drivers/staging/gpib/ni_usb/ni_usb_gpib.c
+++ b/drivers/staging/gpib/ni_usb/ni_usb_gpib.c
@@ -759,7 +759,6 @@ static int ni_usb_write(gpib_board_t *board, uint8_t *buffer, size_t length,
 	if (!out_data)
 		return -ENOMEM;
 	out_data[i++] = 0x0d;
-	complement_count = length;
 	complement_count = length - 1;
 	complement_count = ~complement_count;
 	out_data[i++] = complement_count & 0xff;
-- 
2.43.0

Re: [PATCH] staging: gpib: Remove unused value

[Shuah Khan]

On 10/15/24 15:02, Everest K.C. wrote:
> The variable `complement_count` is assigned a value which is again
> overwritten in the next statement.
> Fix this by removing the first value assigning statement
> 
> This issue was reported by Coverity Scan.
> Report:
> CID 1600790: (#1 of 1): Unused value (UNUSED_VALUE)
> assigned_value: Assigning value from length to complement_count here,
> but that stored value is overwritten before it can be used.
> 
> Fixes: 4e127de14fa7 ("staging: gpib: Add National Instruments USB GPIB driver")
> Signed-off-by: Everest K.C. <everestkc@everestkc.com.np>
> ---
>   drivers/staging/gpib/ni_usb/ni_usb_gpib.c | 1 -
>   1 file changed, 1 deletion(-)
> 
> diff --git a/drivers/staging/gpib/ni_usb/ni_usb_gpib.c b/drivers/staging/gpib/ni_usb/ni_usb_gpib.c
> index 1da263676f2a..e19e18892468 100644
> --- a/drivers/staging/gpib/ni_usb/ni_usb_gpib.c
> +++ b/drivers/staging/gpib/ni_usb/ni_usb_gpib.c
> @@ -759,7 +759,6 @@ static int ni_usb_write(gpib_board_t *board, uint8_t *buffer, size_t length,
>   	if (!out_data)
>   		return -ENOMEM;
>   	out_data[i++] = 0x0d;
> -	complement_count = length;
>   	complement_count = length - 1;
>   	complement_count = ~complement_count;
>   	out_data[i++] = complement_count & 0xff;

Looks good to me.

Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>

thanks,
-- Shuah

Re: [PATCH] staging: gpib: Remove unused value

[Greg KH]

On Tue, Oct 15, 2024 at 03:02:57PM -0600, Everest K.C. wrote:
> The variable `complement_count` is assigned a value which is again
> overwritten in the next statement.
> Fix this by removing the first value assigning statement
> 
> This issue was reported by Coverity Scan.
> Report:
> CID 1600790: (#1 of 1): Unused value (UNUSED_VALUE)
> assigned_value: Assigning value from length to complement_count here,
> but that stored value is overwritten before it can be used.
> 
> Fixes: 4e127de14fa7 ("staging: gpib: Add National Instruments USB GPIB driver")

Thre is no "fix" needed here.  It's not a bug, just a useless operation
(one tha tthe compiler probably just compiles away into nothing.)  So
there is no need for a Fixes: tag, sorry.

thanks,

greg k-h

Re: [PATCH] staging: gpib: Remove unused value

[Everest K.C.]

On Wed, Oct 16, 2024 at 1:37 AM Greg KH <gregkh@linuxfoundation.org> wrote:
>
> On Tue, Oct 15, 2024 at 03:02:57PM -0600, Everest K.C. wrote:
> > The variable `complement_count` is assigned a value which is again
> > overwritten in the next statement.
> > Fix this by removing the first value assigning statement
> >
> > This issue was reported by Coverity Scan.
> > Report:
> > CID 1600790: (#1 of 1): Unused value (UNUSED_VALUE)
> > assigned_value: Assigning value from length to complement_count here,
> > but that stored value is overwritten before it can be used.
> >
> > Fixes: 4e127de14fa7 ("staging: gpib: Add National Instruments USB GPIB driver")
>
> Thre is no "fix" needed here.  It's not a bug, just a useless operation
> (one tha tthe compiler probably just compiles away into nothing.)  So
> there is no need for a Fixes: tag, sorry.
Noted. Will remove the fixes tag and send V2.
> thanks,
>
> greg k-h
Thanks,
Everest K.C.