On Thursday 01 May 2008 11:08:06 Johannes Berg wrote: > > > Hm, unrelated to this... > > But I am wondering what happens if the driver adds a device header to the skb. > > Is that header then also passed up netif_rx()? > > This doesn't happen for b43, as we use the DMA fragmentation to transmit the header, > > but it might happen for zd1211rw and others. > > Hmm. I thought we said that it was supposed to be removed again by the > hardware before TX status reporting. That's what most drivers seem to do > anyway. Ok. I was not aware of that. Is that documented somewhere? I guess we can't WARN_ON()? > > Seems the skb->destructor messes it up. > > Actually, it seems to be outside of mac80211, I put in a WARN_ON() and > got this: Yeah looks like the destructor messes with the data/sizes and disagrees with the way mac80211 handles stuff, in some way. > Badness at include/linux/skbuff.h:392 > NIP: c026ea14 LR: c0273d54 CTR: c026e9e4 > REGS: edfc7c00 TRAP: 0700 Not tainted (2.6.25-wl-06841-g6b3d5c6-dirty) > MSR: 00029032 <EE,ME,IR,DR> CR: 82022444 XER: 00000000 > TASK = edf50e20[3453] 'tcpdump' THREAD: edfc6000 > GPR00: 00000001 edfc7cb0 edf50e20 edfd7700 edfd7700 00000002 edfc7e75 03230306 > GPR08: 02000100 00000168 4dff0200 00000150 22022442 100a6290 100783f8 10078e18 > GPR16: 10078e14 10078e10 100a0000 00000000 00000000 bfe2c9d2 1004d320 bfe2c4b0 > GPR24: 10165070 edfd7724 00000060 00000020 ed8157f0 edfd7700 ed8157f0 edfd7700 > NIP [c026ea14] sock_rfree+0x30/0x94 > LR [c0273d54] skb_release_all+0x98/0x128 > Call Trace: > [edfc7cb0] [10078e10] 0x10078e10 (unreliable) > [edfc7cc0] [c0273d54] skb_release_all+0x98/0x128 > [edfc7cd0] [c0273034] __kfree_skb+0x18/0xc8 > [edfc7ce0] [c02760d0] skb_free_datagram+0x1c/0x54 > [edfc7cf0] [f264d068] packet_recvmsg+0x170/0x1e8 [af_packet] > [edfc7d40] [c026b69c] sock_recvmsg+0xb8/0xf0 > [edfc7e30] [c026b9d0] sys_recvfrom+0x94/0x100 > [edfc7f00] [c026ca08] sys_socketcall+0x114/0x1dc > [edfc7f40] [c00124cc] ret_from_syscall+0x0/0x38 > > johannes > -- 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
