From mboxrd@z Thu Jan  1 00:00:00 1970
From: joe@perches.com (Joe Perches)
Date: Sat, 17 Aug 2013 21:22:27 -0700
Subject: [PATCH v2 02/14] crypto: omap-aes: Add useful debug macros
In-Reply-To: <1376793755-30478-3-git-send-email-joelf@ti.com>
References: <1376793755-30478-1-git-send-email-joelf@ti.com>
 <1376793755-30478-3-git-send-email-joelf@ti.com>
Message-ID: <1376799747.2027.11.camel@joe-AO722>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Sat, 2013-08-17 at 21:42 -0500, Joel Fernandes wrote:
> When DEBUG is enabled, these macros can be used to print variables in integer
> and hex format, and clearly display which registers, offsets and values are
> being read/written , including printing the names of the offsets and their values.
> 
> Note:
> This patch results in a checkpatch error that cannot be fixed.
> ERROR: Macros with multiple statements should be enclosed in a do - while loop
> +#define omap_aes_read(dd, offset)                                      \
> +       __raw_readl(dd->io_base + offset);                              \
> +       pr_debug("omap_aes_read(" #offset ")\n");
> 
> Using do-while loop will break a lot of code such as:
> ret = omap_aes_read(..);

That's where you use a statement expression macro

#define omap_aes_read(dd, offset)					\
({									\
	pr_debug("omap_aes_read("omap_aes_read(" #offset ")\n");	\
	__raw_readl((dd)->iobase + offset);				\
})