2009/2/23 Nick Kossifidis <mickflemm@xxxxxxxxx>: > 2009/2/23 Bob Copeland <me@xxxxxxxxxxxxxxx>: >> On Mon, 23 Feb 2009 00:20:50 +0100, Jiri Slaby wrote >>> On 22.2.2009 22:56, Jiri Slaby wrote: >>> > Well, maybe we should try to reproduce with jumbo packets sent to the >>> > ath5k receiver, since I think it (1) is not very much test-covered code >>> > (2) appears to be related. >>> >>> According to the spec I have for older chip, there is not `done' flag >>> set for descriptors which have `more' flag set. We handle this wrongly. >>> Am I looking correctly, Nick, Luis, Bob? >>> >>> I still don't see what could have caused this though. >> >> As I understand it, yes, we don't do the right thing when the more flag >> is set. We're supposed to keep processing packets until we get one with >> the done flag, and then all of that is supposed to be merged into a single >> packet. Other flags such as the rx rate are only valid on the final >> packet. >> >> However, I did some debugging of this a while ago and concluded that the >> 'jumbo' frames were largely garbage data. The dma buffer size is certainly >> large enough for a standard 802.11 frame and the 'more' flag is only >> supposed to be set if the dma buffer size is too small for a packet. In >> all cases the dma buffer size was 2500+ bytes and the actual contents of >> the packets looked like random values (I did have encryption turned on, >> but there were no 802.11 headers I could see.) >> >> So I am not sure if the jumbo packets are causing bad things to happen, >> or if they are an indication that something bad has already happened. >> > > Hmm can someone test ath5k against an Atheros AP using fast frames ? > Maybe they are jumbo frames but they don't have any header etc so that > they look like one frame after un-fragmentation, documentation says > that the current frame is continued in the next descriptor if more is > set to 1 so i guess next buffer might not have the header. If more = 0 > then it's our last descriptor and only then other fields such as done, > frame receive ok, rssi etc are valid. > > The fact that they are not reported as PHY error packets makes me > wonder why would we have garbage data on our rx buffer. How about the > FRAME_RECEIVE_OK or CRC_ERROR flags (also valid for the last > descriptor) ? Are they set or not ? > Typo alert... rs->rs_more = !!(rx_status->rx_status_0 & AR5K_5212_RX_DESC_STATUS0_MORE); -- GPG ID: 0xD21DB2DB As you read this post global entropy rises. Have Fun ;-) Nick -- 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
