Alexandre Oliva <oliva@lsd.ic.unicamp.br> sent me a patch:

"I see you ran into the same problem I did in brcmfmac.  I wasn't sure a
build with compat-wireless would run into the same problem I did without
it and with Linux-libre.

It's an issue brought about by GCC 4.7's partial-inlining, that ends up
splitting the udelay function just at the wrong spot, in such a way that
some sanity checks for constants fails, and we end up calling
bad_udelay.

This patch fixes the problem.  Feel free to push it upstream if it makes
sense to you."

diff --git a/drivers/net/wireless/brcm80211/brcmfmac/wl_cfg80211.c b/drivers/net/wireless/brcm80211/brcmfmac/wl_cfg80211.c
index 5eddabe..eda1d4e 100644
--- a/drivers/net/wireless/brcm80211/brcmfmac/wl_cfg80211.c
+++ b/drivers/net/wireless/brcm80211/brcmfmac/wl_cfg80211.c
@@ -2463,7 +2463,7 @@ static s32 brcmf_init_iscan(struct brcmf_cfg80211_priv *cfg_priv)
 	return err;
 }
 
-static void brcmf_delay(u32 ms)
+static __always_inline void brcmf_delay(u32 ms)
 {
 	if (ms < 1000 / HZ) {
 		cond_resched();