On Tue, May 10, 2011 at 10:42 AM, Geert Uytterhoeven
[off-list ref] wrote:

On Tue, May 10, 2011 at 11:20, Niels de Vos [off-list ref] wrote:

quoted

When DBG() is used in a simple if-else, the resulting code path
currently depends on the definition of DBG(). Inserting the statement in
a "do { ... } while (0)" prevents this possible misuse.

Signed-off-by: Niels de Vos <redacted>

quoted

--- a/drivers/video/omap2/omapfb/omapfb.h
+++ b/drivers/video/omap2/omapfb/omapfb.h

@@ -34,8 +34,10 @@

 #ifdef DEBUG
 extern unsigned int omapfb_debug;
 #define DBG(format, ...) \
-       if (omapfb_debug) \
-               printk(KERN_DEBUG "OMAPFB: " format, ## __VA_ARGS__)
+       do { \
+               if (omapfb_debug) \
+                       printk(KERN_DEBUG "OMAPFB: " format, ## __VA_ARGS__); \
+       while (0)

Where's the closing '}'?

Good catch! That's in a "fixup!" that I forgot to squash :-/
I'll post an update version in a bit.

quoted

 #else
 #define DBG(format, ...)

BTW, no printf()-style format checking here.

quoted

 #endif

What about using the standard pr_debug()/dev_dbg() instead?
With dynamic debug, it can be enabled at run time.
As a bonus, you get printf()-style format checking if debugging is disabled.

I think removing DBG() and the omapfb_debug module-parameter is surely
a good thing. Unfortunately DBG() is used quite a bit in the code and
replacing them 'll take some more time. I don't know yet when I find
some time to do and test that.

Thanks for the pointers,
Niels

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds
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