| Message ID | 36263581.L8412YxJjp@wuerfel (mailing list archive) |
|---|---|
| State | Accepted |
| Delegated to: | Kalle Valo |
| Headers | show |
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@arndb.de> Acked-by: Nicolas Pitre <nico@linaro.org> > > 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; > > -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, Dec 09, 2015 at 05:42:41PM +0100, 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. I don't think this is good way to "fix" the issue, but also have nothing against to this particular change. Acked-by: Stanislaw Gruszka <sgruszka@redhat.com> -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
> 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@arndb.de> > Acked-by: Nicolas Pitre <nico@linaro.org> > Acked-by: Stanislaw Gruszka <sgruszka@redhat.com> Thanks, applied to wireless-drivers-next.git. Kalle Valo -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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;
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@arndb.de> -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html