Luis R. Rodriguez a écrit : > On Thu, Nov 26, 2009 at 01:47:14AM -0800, Gábor Stefanik wrote: >> 2009/11/25 Benoit PAPILLAULT <benoit.papilla...@free.fr>: >>> Benoit PAPILLAULT a écrit : >>>> TX rate is dropping a lot (like 20 MBits down to 200 kbits/s). Using >>>> another card in monitor mode, I still see packets sent at 54 Mbits rate >>>> however. >>>> >>>> >>> I found out what is wrong with the TX throughput. In fact, when a packet is >>> transmitted at 54 Mbits, the destination send back a 802.11 ACK which is >>> ignored!!! As such, the packet is transmitted at 54 Mbits once again, then >>> twice at 48 Mbits, then twice at 36 Mbits ... and so on down to 1 Mbits. Of >>> course, this divide the throughput by 18 (twice for each 9 rates), leading >>> to 200 - 300 kbits. >>> >>> When implementing proper TX status reporting, needed by minstrel rate >>> control, I also found out that some 802.11 ACK where not received by the >>> driver, but received by the card, leading to inconsistencies in the rate >>> control code. >>> >>> Are there some registers that are responsible for ACK behavior? >>> >>> Regards, >>> Benoit >>> >>> >> ACK handling and retrying is one of the known weak points of the >> zd1211(b) chipset - apparently enabling CR_SNIFFER causes the card to >> ignore ACKs received. Also, the retry plan for unACKed outgoing >> packets (retry count & rates) needs to be uploaded to the device on >> firmware init, and can't be controlled per-packet. >> >> Luis: Any chance of an open firmware release for the ZD1211, similarly >> to what was done for AR9170/ZD1221? That would probably allow for >> fixing these problems. > > I had asked a while back and there is no immediate motivation. I should > note for ar9170 I did all the review myself during my own time, and can't say > I have enough interest to do so for zd1211 as I can use my time to focus > on *newer* items. I'm not even sure about the compiler that was used and > still have yet to see more developer interest on ar9170.fw before making > arguments in favor for any other release. > > BTW use my mcg...@gmail.com address if you want a quicker reponse, I tend > to use my atheros address only for internal stuff. > > Luis >
I understand your concern. So far the current state of the driver is usable to me. Bad performance in monitor mode is not a problem since I only use it for debugging. Regards, Benoit ------------------------------------------------------------------------------ Join us December 9, 2009 for the Red Hat Virtual Experience, a free event focused on virtualization and cloud computing. Attend in-depth sessions from your desk. Your couch. Anywhere. http://p.sf.net/sfu/redhat-sfdev2dev _______________________________________________ Zd1211-devs mailing list - http://zd1211.wiki.sourceforge.net/ Unsubscribe: https://lists.sourceforge.net/lists/listinfo/zd1211-devs