| Message ID | 20180209185100.22511-1-nbd@nbd.name (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Johannes Berg |
| Headers | show |
On 2/9/2018 7:51 PM, Felix Fietkau wrote: > This ensures that mac80211 allocated management frames are properly > aligned, which makes copying them more efficient. > For instance, mt76 uses iowrite32_copy to copy beacon frames to beacon > template memory on the chip. > Misaligned 32-bit accesses cause CPU exceptions on MIPS and should be > avoided. > > Signed-off-by: Felix Fietkau <nbd@nbd.name> > --- > include/net/mac80211.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/include/net/mac80211.h b/include/net/mac80211.h > index 906e90223066..d999b8c8a44b 100644 > --- a/include/net/mac80211.h > +++ b/include/net/mac80211.h > @@ -4149,7 +4149,7 @@ void ieee80211_sta_uapsd_trigger(struct ieee80211_sta *sta, u8 tid); > * The TX headroom reserved by mac80211 for its own tx_status functions. > * This is enough for the radiotap header. Hi Felix, Maybe useful to mention the alignment requirement in this comment block. > */ > -#define IEEE80211_TX_STATUS_HEADROOM 14 > +#define IEEE80211_TX_STATUS_HEADROOM 16 Regards, Arend
On Fri, 2018-02-09 at 20:10 +0100, Arend van Spriel wrote: > > > @@ -4149,7 +4149,7 @@ void ieee80211_sta_uapsd_trigger(struct ieee80211_sta *sta, u8 tid); > > * The TX headroom reserved by mac80211 for its own tx_status functions. > > * This is enough for the radiotap header. > > Hi Felix, > > Maybe useful to mention the alignment requirement in this comment block. > > > */ > > -#define IEEE80211_TX_STATUS_HEADROOM 14 > > +#define IEEE80211_TX_STATUS_HEADROOM 16 > Or better yet, just define it as ALIGN(14, 4) ? johannes
diff --git a/include/net/mac80211.h b/include/net/mac80211.h index 906e90223066..d999b8c8a44b 100644 --- a/include/net/mac80211.h +++ b/include/net/mac80211.h @@ -4149,7 +4149,7 @@ void ieee80211_sta_uapsd_trigger(struct ieee80211_sta *sta, u8 tid); * The TX headroom reserved by mac80211 for its own tx_status functions. * This is enough for the radiotap header. */ -#define IEEE80211_TX_STATUS_HEADROOM 14 +#define IEEE80211_TX_STATUS_HEADROOM 16 /** * ieee80211_sta_set_buffered - inform mac80211 about driver-buffered frames
This ensures that mac80211 allocated management frames are properly aligned, which makes copying them more efficient. For instance, mt76 uses iowrite32_copy to copy beacon frames to beacon template memory on the chip. Misaligned 32-bit accesses cause CPU exceptions on MIPS and should be avoided. Signed-off-by: Felix Fietkau <nbd@nbd.name> --- include/net/mac80211.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)