Re: [PATCH] WAVELAN - compile-time check for struct sizes

[Andrew Morton <akpm@linux-foundation.org>]

On Thu, 7 Feb 2008 14:08:42 -0500
"John W. Linville" <linville@tuxdriver.com> wrote:

> > With your patch applied and arm allmodconfig, this
> > 
> >         BUILD_BUG_ON(sizeof(ha_t) != HA_SIZE);
> > 
> > triggers
> > 
> > Without your patch applied, these two
> > 
> >         BUILD_BUG_ON(sizeof(mmw_t) != MMW_SIZE);
> >         BUILD_BUG_ON(sizeof(ha_t) != HA_SIZE);
> > 
> > are triggering.
> 
> The ha_t one triggers either way?  Hmmm...
> 
> Russell suggested that the ha_t and psa_t packed attributes were
> unnecessary, so I'll include the reduced version just in case the
> above is a typo.
> 
> ---
> 
> From: John W. Linville <linville@tuxdriver.com>
> Subject: [PATCH] wavelan: mark hardware interfacing structures as packed
> 
> Signed-off-by: John W. Linville <linville@tuxdriver.com>

ha_t is still triggering with this patch.

This incremental patch:

--- a/drivers/net/wireless/wavelan.h~a
+++ a/drivers/net/wireless/wavelan.h
@@ -85,7 +85,7 @@ union hacs_u
 #define		HASR_MMC_INTR		0x0002	/* Interrupt request from MMC */
 #define		HASR_MMC_BUSY		0x0004	/* MMC busy indication */
 #define		HASR_PSA_BUSY		0x0008	/* LAN parameter storage area busy */
-};
+} __attribute__((packed));
 
 typedef struct ha_t	ha_t;
 struct ha_t
_

fixes things up.  If forces `union hacs_u' to be two bytes, not four.