| Message ID | 20191201181716.61892-1-pgreco@centosproject.org (mailing list archive) |
|---|---|
| State | Accepted |
| Delegated to: | Felix Fietkau |
| Headers | show |
| Series | [v1] mt76: mt7615: Fix build with older compilers | expand |
Hello! On 01.12.2019 21:17, Pablo Greco wrote: > Some compilers (tested with 4.8.5 from CentOS 7) fail properly process Fail to? > FIELD_GET inside an inline function, which ends up in a BUILD_BUG_ON. > Convert inline function to a macro. > > Fixes commit bf92e7685100 ("mt76: mt7615: add support for per-chain > signal strength reporting") Should be: Fixes: bf92e7685100 ("mt76: mt7615: add support for per-chain signal strength reporting") Do not ever break up the Fixes: line and don't insert empty lines between it and other tags. > Reported in https://lkml.org/lkml/2019/9/21/146 > > Reported-by: kbuild test robot <lkp@intel.com> > Signed-off-by: Pablo Greco <pgreco@centosproject.org> [...] MBR, Sergei
Pablo Greco <pgreco@centosproject.org> writes: > Some compilers (tested with 4.8.5 from CentOS 7) fail properly process > FIELD_GET inside an inline function, which ends up in a BUILD_BUG_ON. > Convert inline function to a macro. > > Fixes commit bf92e7685100 ("mt76: mt7615: add support for per-chain > signal strength reporting") > Reported in https://lkml.org/lkml/2019/9/21/146 > > Reported-by: kbuild test robot <lkp@intel.com> > Signed-off-by: Pablo Greco <pgreco@centosproject.org> > --- > drivers/net/wireless/mediatek/mt76/mt7615/mac.c | 5 +---- > 1 file changed, 1 insertion(+), 4 deletions(-) > > diff --git a/drivers/net/wireless/mediatek/mt76/mt7615/mac.c b/drivers/net/wireless/mediatek/mt76/mt7615/mac.c > index c77adc5d2552..77e395ca2c6a 100644 > --- a/drivers/net/wireless/mediatek/mt76/mt7615/mac.c > +++ b/drivers/net/wireless/mediatek/mt76/mt7615/mac.c > @@ -13,10 +13,7 @@ > #include "../dma.h" > #include "mac.h" > > -static inline s8 to_rssi(u32 field, u32 rxv) > -{ > - return (FIELD_GET(field, rxv) - 220) / 2; > -} > +#define to_rssi(field, rxv) ((FIELD_GET(field, rxv) - 220) / 2) What about u32_get_bits() instead of FIELD_GET(), would that work? I guess chances for that is slim, but it's always a shame to convert a function to a macro so we should try other methods first. Or even better if we could fix FIELD_GET() to work with older compilers.
On 2/12/19 06:18, Sergei Shtylyov wrote: > Hello! > > On 01.12.2019 21:17, Pablo Greco wrote: > >> Some compilers (tested with 4.8.5 from CentOS 7) fail properly process > > Fail to? Right > >> FIELD_GET inside an inline function, which ends up in a BUILD_BUG_ON. >> Convert inline function to a macro. >> >> Fixes commit bf92e7685100 ("mt76: mt7615: add support for per-chain >> signal strength reporting") > > Should be: > > Fixes: bf92e7685100 ("mt76: mt7615: add support for per-chain signal > strength reporting") > > Do not ever break up the Fixes: line and don't insert empty lines > between it and other tags. Ack, I'll fix those for v2 > >> Reported in https://lkml.org/lkml/2019/9/21/146 >> >> Reported-by: kbuild test robot <lkp@intel.com> >> Signed-off-by: Pablo Greco <pgreco@centosproject.org> > [...] > > MBR, Sergei Thanks, Pablo
On 2/12/19 06:25, Kalle Valo wrote: > Pablo Greco <pgreco@centosproject.org> writes: > >> Some compilers (tested with 4.8.5 from CentOS 7) fail properly process >> FIELD_GET inside an inline function, which ends up in a BUILD_BUG_ON. >> Convert inline function to a macro. >> >> Fixes commit bf92e7685100 ("mt76: mt7615: add support for per-chain >> signal strength reporting") >> Reported in https://lkml.org/lkml/2019/9/21/146 >> >> Reported-by: kbuild test robot <lkp@intel.com> >> Signed-off-by: Pablo Greco <pgreco@centosproject.org> >> --- >> drivers/net/wireless/mediatek/mt76/mt7615/mac.c | 5 +---- >> 1 file changed, 1 insertion(+), 4 deletions(-) >> >> diff --git a/drivers/net/wireless/mediatek/mt76/mt7615/mac.c b/drivers/net/wireless/mediatek/mt76/mt7615/mac.c >> index c77adc5d2552..77e395ca2c6a 100644 >> --- a/drivers/net/wireless/mediatek/mt76/mt7615/mac.c >> +++ b/drivers/net/wireless/mediatek/mt76/mt7615/mac.c >> @@ -13,10 +13,7 @@ >> #include "../dma.h" >> #include "mac.h" >> >> -static inline s8 to_rssi(u32 field, u32 rxv) >> -{ >> - return (FIELD_GET(field, rxv) - 220) / 2; >> -} >> +#define to_rssi(field, rxv) ((FIELD_GET(field, rxv) - 220) / 2) > What about u32_get_bits() instead of FIELD_GET(), would that work? I > guess chances for that is slim, but it's always a shame to convert a > function to a macro so we should try other methods first. Anything that doesn't check field at build time should work, but between losing a check, or turning an inline into a macro, I'd rather use the macro. > Or even better if we could fix FIELD_GET() to work with older compilers. > The problem is not FIELD_GET itself, is that the compiler is trying to use "field" as a variable, instead as the macro expansion of GENMASK, as if the function wasn't inline. In the linked page you can see this message BUILD_BUG_ON failed: (((field) + (1ULL << (__builtin_ffsll(field) - 1))) & (((field) + (1ULL << (__builtin_ffsll(field) - 1))) - 1)) != 0 _compiletime_assert(condition, msg, __compiletime_assert_, __LINE__) which is is not right, because "field" should never be used for that check. Pablo.
diff --git a/drivers/net/wireless/mediatek/mt76/mt7615/mac.c b/drivers/net/wireless/mediatek/mt76/mt7615/mac.c index c77adc5d2552..77e395ca2c6a 100644 --- a/drivers/net/wireless/mediatek/mt76/mt7615/mac.c +++ b/drivers/net/wireless/mediatek/mt76/mt7615/mac.c @@ -13,10 +13,7 @@ #include "../dma.h" #include "mac.h" -static inline s8 to_rssi(u32 field, u32 rxv) -{ - return (FIELD_GET(field, rxv) - 220) / 2; -} +#define to_rssi(field, rxv) ((FIELD_GET(field, rxv) - 220) / 2) static struct mt76_wcid *mt7615_rx_get_wcid(struct mt7615_dev *dev, u8 idx, bool unicast)
Some compilers (tested with 4.8.5 from CentOS 7) fail properly process FIELD_GET inside an inline function, which ends up in a BUILD_BUG_ON. Convert inline function to a macro. Fixes commit bf92e7685100 ("mt76: mt7615: add support for per-chain signal strength reporting") Reported in https://lkml.org/lkml/2019/9/21/146 Reported-by: kbuild test robot <lkp@intel.com> Signed-off-by: Pablo Greco <pgreco@centosproject.org> --- drivers/net/wireless/mediatek/mt76/mt7615/mac.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-)