On Fri, 2018-03-23 at 11:02 -0400, Tyler Gray wrote: > I'm positive we're just in monitor mode. [snip] Ok, it was just a thought. > To be clear, I'm not claiming I can set two devices up anywhere, > anytime, and run this test and see huge gaps in beacons, but we've > tested across multiple devices and multiple brands of devices with > 7265 cards, and we have data collected in locations that are miles > apart that show the same behavior, so I'm confident this isn't just > one bad card or one incredibly unlucky setup that shows the problem. > I have determined spots where I'm far more likely to see the issue, > but I'll maintain that outside of a pathologically bad environment, I > should be able to see beacons from 6 feet away. > > You mentioned the firmware can suppress beacons for powersaving. Is > there any debug I could look at to see if that was happening? I > posted some fw_rx_stats, would those counters be incremented before > that filtering would happen? I just watched the counters during a > good period and a bad period. In the "good" period I saw 15 CCK > packets/second, which is what I'd expect for my AP beaconing plus some > some probe responses and some beacons from the adjacent channel. > During the bad period the firmware saw 2 CCK packets in 7 seconds, and > none of the error counters for the bad period showed an additional 100 > packets lost for any reason. The two periods had fairly similar > plcp_err stats. I'd have to check. ISTR being told that 8260 devices would make much better sniffers - any chances you have one of those to try? > As a side note, if I have a device connect to the AP and run iperf to > generate data, I'll capture an average of 99% of the data packets, yet > I'll often see 0 beacons while the transfer is happening. So it's not > that I can't receive packets at all, and capturing those data packets > should be a far harder task, but it seems beacons get dropped in a > variety of cases and I can't determine why. Interesting. > Are there any known conflicts between the bluetooth and the wifi? Is > there an easy answer to the best (lowest level) way to disable > bluetooth if so? rmmod btusb ;-) I don't really know for sure, but I wouldn't really expect BT to affect single-chain RX performance much. Perhaps you could file a bug on bugzilla.kernel.org so we can track this better. johannes
