Re: [Outreachy kernel] [PATCH 4/4] staging: rtl8723bs: Change the type and use of a variable

From: Greg KH
Date: Sat Apr 10 2021 - 09:55:55 EST


On Sat, Apr 10, 2021 at 03:53:38PM +0200, Fabio M. De Francesco wrote:
> On Saturday, April 10, 2021 3:24:43 PM CEST Julia Lawall wrote:
> > On Sat, 10 Apr 2021, Fabio M. De Francesco wrote:
> > > On Saturday, April 10, 2021 2:12:28 PM CEST Julia Lawall wrote:
> > > > On Sat, 10 Apr 2021, Fabio M. De Francesco wrote:
> > > > > On Saturday, April 10, 2021 1:37:30 PM CEST Julia Lawall wrote:
> > > > > > > That variable has global scope and is assigned at least in:
> > > > > > What do you mean by global scope? None of the following look
> > > > > > like
> > > > > > references to global variables.
> > > > > >
> > > > > > julia
> > > > >
> > > > > I just mean that fw_current_in_ps_mode is a field of a struct in a
> > > > > .h
> > > > > file included everywhere in this driver and that the functions whom
> > > > > the following assignments belong to have not the "static" type
> > > > > modifier.
> > > >
> > > > OK, but a field in a structure is not a variable, and this is not
> > > > what
> > > > scope means.
> > >
> > > You're right, a field in a structure is not a variable.
> > >
> > > > int x;
> > > >
> > > > outside of anything is a global variable (global scope).
> > > >
> > > > int foo() {
> > > >
> > > > int x;
> > > > ...
> > > >
> > > > }
> > > >
> > > > Here x is a local variable. Its scope is the body of the function.
> > > >
> > > > int foo() {
> > > >
> > > > if (abc) {
> > > >
> > > > int x;
> > > > ...
> > > >
> > > > }
> > > >
> > > > }
> > > >
> > > > Here x is a local variable, but its scope is only in the if branch.
> > >
> > > And you're right again: I needed a little refresh of my knowledge of C.
> > >
> > > I've searched again in the code for the purpose of finding out if that
> > > struct is initialized with global scope but I didn't find anything. I
> > > didn't even find any dynamic allocation within functions that returns
> > > pointers to that struct.
> > >
> > > Therefore, according to Greg's request, I'll delete that stupid 'if'
> > > statement in the patch series v2 that I'm about to submit.
> >
> > I'm really not clear on why the if should be deleted.
> >
> > julia
> >
> I'm supposed to delete it because of the review made by Greg. In a couple
> of previous messages he wrote:
>
> "If this is only checked, how can it ever be true? Who ever sets this
> value?"
>
> and then:
>
> "Just delete the variable from the structure entirely and when it is
> used.".
>
> However, like you, I'm not sure yet.

I don't think any of us are, try fixing up what you think is right and
resend and we can go from there :)