Re: [PATCH 1/6] pcmcia/3c574_cs: Fix dubious bitfield warning

[Richard Knutsson]

Alan Cox wrote:
> On Tue, 11 Dec 2007 05:32:38 +0100 (MET)
> Richard Knutsson <ricknu-0@xxxxxxxxxxxxxx> wrote:
>
>   
> > Fixing:
> >   CHECK   drivers/net/pcmcia/3c574_cs.c
> > drivers/net/pcmcia/3c574_cs.c:194:13: warning: dubious bitfield without explicit `signed' or `unsigned'
> > drivers/net/pcmcia/3c574_cs.c:196:14: warning: dubious bitfield without explicit `signed' or `unsigned'
> >
> > Signed-off-by: Richard Knutsson <ricknu-0@xxxxxxxxxxxxxx>
> > ---
> > Is there a reason for not doing it this way?
> >     
>
> How is the endianness handled here (I suspect its always been broken)
>   
Guess so, but it should not handle the endians differently with such a 
change, does it?
>   
> > diff --git a/drivers/net/pcmcia/3c574_cs.c b/drivers/net/pcmcia/3c574_cs.c
> > index ad134a6..97b6daa 100644
> > --- a/drivers/net/pcmcia/3c574_cs.c
> > +++ b/drivers/net/pcmcia/3c574_cs.c
> > @@ -190,10 +190,10 @@ enum Window3 {			/* Window 3: MAC/config bits. */
> >  union wn3_config {
> >  	int i;
> >  	struct w3_config_fields {
> > -		unsigned int ram_size:3, ram_width:1, ram_speed:2, rom_size:2;
> > -		int pad8:8;
> > -		unsigned int ram_split:2, pad18:2, xcvr:3, pad21:1, autoselect:1;
> > -		int pad24:7;
> > +		u8 ram_size:3, ram_width:1, ram_speed:2, rom_size:2;
> > +		u8 pad8;
> > +		u8 ram_split:2, pad18:2, xcvr:3, pad21:1;
> > +		u8 autoselect:1, pad24:7;
> >     
>
> Just changing the int pad to unsigned int pad would be safer in terms of
> not causing changes. Simply delcaring a 32bit field and bit masks to
> and/or into it is probably a lot saner in the general case.
>   
Thought about it before and with the endian-issue it seem like a better 
solution.
So, something like this?

Fixing:
  CHECK   drivers/net/pcmcia/3c574_cs.c
drivers/net/pcmcia/3c574_cs.c:194:13: warning: dubious bitfield without explicit `signed' or `unsigned'
drivers/net/pcmcia/3c574_cs.c:196:14: warning: dubious bitfield without explicit `signed' or `unsigned'

Signed-off-by: Richard Knutsson <ricknu-0@xxxxxxxxxxxxxx>
---
Moved 'autoselect' to the last line to make every line 8 bits.
Is there a reason for not doing it this way?


diff --git a/drivers/net/pcmcia/3c574_cs.c b/drivers/net/pcmcia/3c574_cs.c
index ad134a6..e549427 100644
--- a/drivers/net/pcmcia/3c574_cs.c
+++ b/drivers/net/pcmcia/3c574_cs.c
@@ -190,10 +190,10 @@ enum Window3 {			/* Window 3: MAC/config bits. */
 union wn3_config {
 	int i;
 	struct w3_config_fields {
-		unsigned int ram_size:3, ram_width:1, ram_speed:2, rom_size:2;
-		int pad8:8;
-		unsigned int ram_split:2, pad18:2, xcvr:3, pad21:1, autoselect:1;
-		int pad24:7;
+		u32 ram_size:3, ram_width:1, ram_speed:2, rom_size:2,
+		    pad8:8,
+		    ram_split:2, pad18:2, xcvr:3, pad21:1,
+		    autoselect:1, pad24:7;
 	} u;
 };