wifi: b43legacy: work around stack frame size warning

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I came across a rare warning in the b43legacy driver while building
randconfig kernels using clang-21.1.8, with KASAN enabled:

drivers/net/wireless/broadcom/b43legacy/main.c:3250:12: error: stack frame size (1392) exceeds limit (1280) in 'b43legacy_wireless_core_init' [-Werror,-Wframe-larger-than]
 3250 | static int b43legacy_wireless_core_init(struct b43legacy_wldev *dev)
      |            ^

There are no actual large variables on the stack here, just excessive
spills, and the code looks fine otherwise, so this is really an
optimization quirk in the compiler. Marking the prepare_phy_data_for_init()
function as noinline completely avoids the issue, with no function in
this file using more than 200 bytes of stack space, same as without KASAN.

Link: https://pastebin.com/raw/KpV124Ep # .config
Link: https://pastebin.com/CxWfsBN0 # assembler output, truncated
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://patch.msgid.link/20260925130749.4191347-1-arnd@kernel.org
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

...

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Arnd Bergmann 2026-09-25 15:07:36 +02:00 • committed by Johannes Berg

parent d4b21975f4

commit f07554557f

1 changed files with 2 additions and 1 deletions

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drivers/net/wireless/broadcom/b43legacy/main.c

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