On Tue, Jul 27, 2010 at 9:39 AM, Felix Fietkau <nbd@xxxxxxxxxxx> wrote: > On 2010-07-27 6:19 PM, Luis R. Rodriguez wrote: >>> + * @NL80211_ATTR_WIPHY_ANTENNA_TX: Bitmap of allowed antennas for transmitting. >>> + * Each bit represents one antenna, starting with antenna 1 at the first >>> + * bit. If the bitmap is zero (0), the TX antenna follows RX diversity. >> >> What about for 802.11n? What if you want to disable TX? > Disabling tx shouldn't be handled by the antenna setting, IMHO. > >>> + * If multiple antennas are selected all selected antennas have to be used >>> + * for transmitting (801.11n multiple TX chains). >> >> I rather call this TX / RX chainmask then. > Well, for legacy hardware, these aren't really chains, as there is only > one rx and one tx path, just with switching onto multiple antennas. > >>> + * Drivers may reject configurations they cannot support. >>> + * >>> + * @NL80211_ATTR_WIPHY_ANTENNA_RX: Bitmap of allowed antennas for receiving. >>> + * Each bit represents one antenna, starting with antenna 1 at the first >>> + * bit. If multiple antennas are selected in the bitmap, 802.11n devices >>> + * should use multiple RX chains on these antennas, while non-802.11n >>> + * drivers should use antenna diversity between these antennas. >> >> What about TX beamforming, and STBC? > Disabling one antenna/chain on a two-chain device would naturally > disable TxBF and STBC as well, since it limits the number of available > chains. The driver should simply act as if the disabled chains didn't exist. That would work. >> Unless 802.11n is completely dealt with I really prefer this patch to >> only address legacy. Otherwise I see sloppyness and inconsistencies on >> supporting this feature throughout different drivers. I'd like to >> avoid that at all costs on nl80211. What you are trying to address is >> legacy antenna setup, not 802.11n RX/TX chainmask dynamic settings so >> I'd really try to avoid it unless you really want to address all >> aspects of chain configuration for 802.11n and even then what I'm >> leading on to say is I think you'll see if you try to address both it >> just gets messy. > I think 802.11n is already completely dealt with if you treat this as > the chainmask on 11n devices. Its fine by me if the above cases are also embedded into the documentation, just don't want these questions lingering. I can't think of other 802.11n special cases. Luis -- 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
