On Thu, Feb 02, 2012 at 02:09:10PM -0800, Adrian Chadd wrote: > Hi, questions below: > > On 1 February 2012 08:05, Rajkumar Manoharan <rmanohar@xxxxxxxxxxxxxxxx> wrote: > > > > This patch improves ANI operations by switching among the immunity > > levels based on PHY errors and beacon rssi which will adjust receiver > > desensitizing parameters. The changes are > > What environments are you seeing this bad behaviour in? I'd just like > to be sure that this won't mess up the behaviour of ANI for other > chips, other environments and other operating modes. > The actual test was done in AP mode in controlled environment with rx signal level of -50 dBm and with interference of -45 dBm at STA side. In such scenario beacon miss was observered and drastic hit in throughput at OFDM ani level 9 after enabling the Weak signal detection. Not changing the any of weak signal detection thresholds and retaining the ini values improved the throughput at higher ANI levels. > > * Irrespective of opmode, the Weak Signal Detection is with the current > > immunity level value. > Again with AP mode enabling/disabling the Weak signal detection is not working. It was verified from the register (use_self_corr_low). So that it will configure the WSD with current ofdm immunity level, if there is mismatch b/w configured WSD state and selected immunity level's WSD state. > I didn't think that weak signal detection was a single bit in the PHY. > It looks like you've just deleted all the threshold settings and are > turning on/off using low self correlation. > As menstion above, the thresh values are continue to retain the init values. Based on the test results, it is enough to update use_self_corr_low state. > Have a read of the (very early, AR5212 era?) ANI patent: > > http://www.freepatentsonline.com/7349503.pdf > > If this has changed (ie, if in Osprey it's done differently) then it > should likely be documented in the driver somewhere. > > IF this all works then great, but I'd really like to try and better > understand/document the "why" aspects of it. ANI is .. fiddly, and > there aren't any tools available for ath9k (+freebsd) wireless > developers to really understand the impact of ANI. > -- Rajkumar -- 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
