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

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

On Fri, Feb 22, 2008 at 7:07 AM, Michael Buesch <mb@bu3sch.de> wrote:
> On Friday 22 February 2008 05:24:32 Gordon Farquharson wrote:
>  > On Wed, Feb 20, 2008 at 12:37 PM, Sam Ravnborg <sam@ravnborg.org> wrote:
>  >
>  > >  Option 1) is the worst of the three as that can cost
>  > >  of many hours bug-hunting.
>  > >  Option 3) may seem optimal but I do not like to add more
>  > >  complexity to this part of the build. And really I do not
>  > >  know a reliable way to detech when we do cross builds anyway.
>  > >
>  > >  Leaving us with option 2) that is simple, strighforward and harmless.
>  >
>  > Are you willing to sign off on and commit the patch?
>
>  Only with a big fat comment added that the alignment is only needed
>  because of a broken sanity check in file2alias.c.

How about 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
change 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
http://lkml.org/lkml/2008/2/18/481 for discussion).

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

---

diff --git a/include/linux/mod_devicetable.h b/include/linux/mod_devicetable.h
index 139d49d..93083ad 100644
--- a/include/linux/mod_devicetable.h
+++ b/include/linux/mod_devicetable.h
@@ -351,7 +351,9 @@ struct sdio_device_id {
 struct ssb_device_id {
        __u16   vendor;
        __u16   coreid;
-       __u8    revision;
+       /* Explicit padding to support cross-compilation. */
+       __u8    revision
+               __attribute__((aligned(sizeof(__u32))));
 };
 #define SSB_DEVICE(_vendor, _coreid, _revision)  \
        { .vendor = _vendor, .coreid = _coreid, .revision = _revision, }

-- 
Gordon Farquharson
GnuPG Key ID: 32D6D676