Re: [PATCH] iwlegacy: mark il_adjust_beacon_interval as noinline

[Nicolas Pitre]

On Wed, 9 Dec 2015, Arnd Bergmann wrote:

> With the new optimized do_div() code, some versions of gcc
> produce obviously incorrect code that leads to a link error
> in iwlegacy/common.o:
> 
> drivers/built-in.o: In function `il_send_rxon_timing':
> :(.text+0xa6b4d4): undefined reference to `____ilog2_NaN'
> :(.text+0xa6b4f0): undefined reference to `__aeabi_uldivmod'
> 
> In a few thousand randconfig builds, I have seen this problem
> a couple of times in this file, but never anywhere else in the
> kernel, so we can try to work around this in the only file
> that shows the behavior, by marking the il_adjust_beacon_interval
> function as noinline, which convinces gcc to use the unoptimized
> do_div() all the time.
> 
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>

Acked-by: Nicolas Pitre <nico@xxxxxxxxxx>

> 
> diff --git a/drivers/net/wireless/intel/iwlegacy/common.c b/drivers/net/wireless/intel/iwlegacy/common.c
> index 887114582583..6308bb217454 100644
> --- a/drivers/net/wireless/intel/iwlegacy/common.c
> +++ b/drivers/net/wireless/intel/iwlegacy/common.c
> @@ -3602,7 +3602,7 @@ il_is_ht40_tx_allowed(struct il_priv *il, struct ieee80211_sta_ht_cap *ht_cap)
>  }
>  EXPORT_SYMBOL(il_is_ht40_tx_allowed);
>  
> -static u16
> +static u16 noinline
>  il_adjust_beacon_interval(u16 beacon_val, u16 max_beacon_val)
>  {
>  	u16 new_val;
> 
> 
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