Re: [RFC] [PATCH] Fix b43 driver build for arm

["Gordon Farquharson" <gordonfarquharson@gmail.com>]

On Fri, Feb 22, 2008 at 10:51 PM, Michael Buesch <mb@bu3sch.de> wrote:
>  A big fat comment is something like that:
>
>  /* Explicit padding to support a broken sanity check in file2alias.c.
>   * The check will compare the size of the structure in the kernel
>   * object file to the userspace the kernel is compiled on.
>   * This breaks on cross-compilation. This padding is a workaround
>   * for this. */

---

Align the members of the SSB device structure to a 32 bit boundary so
that the b43 driver can be built for arm using a cross compiler. This
alignment is required so that the test in scripts/mod/file2alias.c
that checks that the size of the device ID type against the size of
the section in the object file succeeds (see comment and
http://lkml.org/lkml/2008/2/18/481 for explanation).

Signed-off-by: Gordon Farquharson <gordonfarquharson@gmail.com>

---

diff --git a/include/linux/mod_devicetable.h b/include/linux/mod_devicetable.h
index 139d49d..208d49a 100644
--- a/include/linux/mod_devicetable.h
+++ b/include/linux/mod_devicetable.h
@@ -351,7 +351,13 @@ struct sdio_device_id {
 struct ssb_device_id {
 	__u16	vendor;
 	__u16	coreid;
-	__u8	revision;
+	/* Explicit padding to support a broken sanity check in file2alias.c.
+	 * The check compares the size of the structure in the kernel
+	 * object file to the size of the structure reported in userspace for
+	 * the system on which the kernel is compiled. The check breaks on
+	 * cross-compilation, and the padding is a workaround for this. */
+	__u8	revision
+		__attribute__((aligned(sizeof(__u32))));
 };
 #define SSB_DEVICE(_vendor, _coreid, _revision)  \
 	{ .vendor = _vendor, .coreid = _coreid, .revision = _revision, }

-- 
Gordon Farquharson
GnuPG Key ID: 32D6D676