On Monday 24 December 2007 22:57:03 Johannes Berg wrote: > On Mon, 2007-12-24 at 22:45 +0100, Johannes Berg wrote: > > > [ 98.415423] ------------[ cut here ]------------ > > > [ 98.415627] Badness at e221c924 [verbose debug info unavailable] > > > > > [ 98.416905] NIP [e221c924] __ieee80211_rx+0x48c/0xd44 [mac80211] > > > > ieee80211_rx_monitor() is inlined into __ieee80211_rx() and that +0x48c > > is quite a high number, so I'm guessing it's this: > > > > /* > > * Drivers are required to align the payload data to a four-byte > > * boundary, so the last two bits of the address where it starts > > * may not be set. The header is required to be directly before > > * the payload data, padding like atheros hardware adds which is > > * inbetween the 802.11 header and the payload is not supported, > > * the driver is required to move the 802.11 header further back > > * in that case. > > */ > > hdrlen = ieee80211_get_hdrlen(rx.fc); > > WARN_ON_ONCE(((unsigned long)(skb->data + hdrlen)) & 3); > > Yup, that's what it is, Michael sent me the assembly, __ieee80211_rx > starts at 0x1990 and we find at 0x1990+0x48c == 0x1e1c > > > 1df8: 48 00 00 01 bl 1df8 <__ieee80211_rx+0x468> > 1df8: R_PPC_REL24 ieee80211_get_hdrlen > 1dfc: 80 18 00 a0 lwz r0,160(r24) > 1e00: 7c 00 1a 14 add r0,r0,r3 > 1e04: 70 09 00 03 andi. r9,r0,3 > 1e08: 41 a2 00 2c beq+ 1e34 <__ieee80211_rx+0x4a4> > 1e0c: 3d 20 00 00 lis r9,0 > 1e0e: R_PPC_ADDR16_HA .sbss > 1e10: 80 09 00 00 lwz r0,0(r9) > 1e12: R_PPC_ADDR16_LO .sbss > 1e14: 7c 00 00 34 cntlzw r0,r0 > 1e18: 54 00 d9 7e rlwinm r0,r0,27,5,31 > 1e1c: 0f 00 00 00 twnei r0,0 > > which is exactly the WARN_ON_ONCE above. So zd1211rw-mac80211 is pushing some unaligned data up the RX path, hm. -- Greetings Michael. - To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
