2009/4/16 Arnd Hannemann <hannemann@xxxxxxxxxxxxxxxxxxx>: > Gábor Stefanik wrote: >> On Thu, Apr 16, 2009 at 3:11 PM, Nick Kossifidis <mickflemm@xxxxxxxxx> wrote: >> >>> 2009/4/16 Hans Maes <Hans@xxxxxxxxx>: >>> >>>> Hello, >>>> >>>> I'm not sure this is the correct place to ask my question, but I've been >>>> searching on google for ages now and can't seem to find an answer so I'm >>>> asking it here. >>>> If not, please yell at me and tell me where to go whine instead ;-) >>>> >>>> I'm using CM11 a/b/g cards with the Atheros AR5414A Chip, which have 2 >>>> antenna connectors. >>>> I only have 1 antenna connected to the MAIN connector. >>>> Running a self compiled 2.6.29 kernel on a few debian lenny boxes with ath5k >>>> module for the wireless cards, set up in mesh mode. >>>> Seems to work fine on the test bench, but behaves rather poorly in >>>> production environment. >>>> Everything related to the mesh network setup seems to work, but I have about >>>> 40% - 60% packet loss on the entire netwerk (about 15 nodes) >>>> >>>> I'm guessing this has something to do with the antenna diversity setting. >>>> >>>> Can anybody tell me how to tell the ath5k module to disable antenna >>>> diversity and only use the MAIN antenna ? >>>> >>>> If this is a RTFM thingie, then I apologize, I just can't seem to find it >>>> anywhere. >>>> >>>> Please reply to my personal e-mail address as well, I'm not subscribed to >>>> the list. >>>> >>>> Thanks for your help. >>>> >>>> Regards, >>>> >>>> Hans >>>> >>> After this patch... >>> https://lists.ath5k.org/pipermail/ath5k-devel/2009-April/002264.html >>> >>> It's possible to tell the driver to use one fixed antenna (in your >>> case its fixed antenna A). Just change... >>> ath5k_hw_set_antenna_mode(ah, AR5K_ANTMODE_DEFAULT); >>> >>> with >>> ath5k_hw_set_antenna_mode(ah, AR5K_ANTMODE_FIXED_A); >>> >>> we will have a better way to change this in the future ;-) >>> >> >> I wonder if just exporting that as a modparam is a good-enough >> choice... though perhaps the best solution would be something like "iw >> phy phy0 antenna 1 up/down". Or perhaps we should make antenna >> diversity depend on the PCI ID, defaulting to 1 antenna when diversity >> support cannot be determined. >> >> > modparam seems somewhat broken, thinking of multiple wireless cards... > My feature request would be to allow setup fixed txantenna only for > broadcast/multicast frames. Well such frames should be sent on all antennas i believe (i did some experiments and it seems we can force this by writing 0xf on antenna field of tx descriptor). > I think it would work for almost all setups, even if only > one antenna connector is used, as diversity logic > will naturally handle unicast frames right. Or did I miss something? > > BTW: is it theoretically possible to turn off RX antenna diversity, and > what would be the potential gain? > Yes, check out the patch. The only problem i see with rx diversity in some cases is when you get a frame on the wrong antenna, this can lead on updating tx antenna (based on acks etc) which can lead to missed frames. -- 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
