Re: [PATCH] Staging: dgnc: constify attribute_group structures

[Greg KH <gregkh@linuxfoundation.org>]

On Thu, Sep 29, 2016 at 08:18:54PM +0530, Bhumika Goyal wrote:
> Check for attribute_group structures that are only passed as a second
> argument to the functions sysfs_remove_group and sysfs_create_group. As
> these arguments are constant so, attribute_group structures having this
> property  can also be made constant.
> Done using coccinelle:
> 
> @r1 disable optional_qualifier @
> identifier i;
> position p;
> @@
> static struct attribute_group i@p = {...};
> 
> @ok1@
> identifier r1.i;
> position p;
> expression e1;
> @@
> (
> sysfs_remove_group(e1,&i@p)
> |
> sysfs_create_group(e1,&i@p)
> )
> 
> @bad@
> position p!={r1.p,ok1.p};
> identifier r1.i;
> @@
> i@p
> 
> @depends on !bad disable optional_qualifier@
> identifier r1.i;
> @@
> static
> +const
> struct attribute_group i={...};
> 
> @depends on !bad disable optional_qualifier@
> identifier r1.i;
> @@
> +const
> struct attribute_group i;
> 
> File size before:
>    text	   data	    bss	    dec	    hex	filename
>    6248	   1024	      0	   7272	   1c68
> drivers/staging/dgnc/dgnc_sysfs.o
> 
> File size after:
>    text	   data	    bss	    dec	    hex	filename
>    6288	    960	      0	   7248	   1c50
> drivers/staging/dgnc/dgnc_sysfs.o
> 
> Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
> ---
>  drivers/staging/dgnc/dgnc_sysfs.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/dgnc/dgnc_sysfs.c b/drivers/staging/dgnc/dgnc_sysfs.c
> index a83e0e4..290bf6e 100644
> --- a/drivers/staging/dgnc/dgnc_sysfs.c
> +++ b/drivers/staging/dgnc/dgnc_sysfs.c
> @@ -677,7 +677,7 @@ static struct attribute *dgnc_sysfs_tty_entries[] = {
>  	NULL
>  };
>  
> -static struct attribute_group dgnc_tty_attribute_group = {
> +static const struct attribute_group dgnc_tty_attribute_group = {
>  	.name = NULL,
>  	.attrs = dgnc_sysfs_tty_entries,
>  };

I'll take this patch, but all of these sysfs files should be removed
from the driver, as there are standard ways of getting this information
from a tty device that is not using this interface.

So if you want to send a follow-on patch, removing all of them, I would
really appreciate it.

thanks,

greg k-h