Date: Tue, 3 Jul 2018 18:15:27 -0400 From: Farhan Khan <khanzf@gmail.com> To: freebsd-wireless@freebsd.org Subject: ifconfig scan returns no results - tracing rtwn(4)'s scanning execution flow Message-ID: <CAFd4kYCHGWdGqGBv3Kns2674c4SAzzYuQjJf3OEVD=i0cTFF8Q@mail.gmail.com>
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Hi all, I'm having trouble tracing the scanning code. My extension to rtl8188ee currently returns immediately after running 'ifconfig wlan0 scan' without any identified BSSes. I am not yet certain why and am trying to figure out why. I suspect something is immediately failing and immediately returning. However, my tracing the code makes it appear circular and I am not certain where ieee80211(9) reaches into the kernel to perform the scan. My understanding of process flow: * ieee80211_swscan_attach queues a task for scan_curchan_task. * scan_curchan_task runs ic->ic_set_channel (733) and then immediately scans the channel with ic->ic_scan_curchan (line 745) in ieee80211_scan_sw.c. * ic->ic_scan_curchan is a pointer to to rtwn_scan_curchan() in if_rtwn.c (line 287). * rtwn_scan_curchan() almost immediately runs sc->sc_scan_curchan(), which is itself a pointer to ic->ic_scan_curchan. That's circular. Where did I go wrong? If rtwn(4)'s scanning is performed by the kernel, where does it reach into the kernel? I am trying to figure out where the failure in the lack of results from "ifconfig wlan0 scan" originates from. (Oh, lest anyone asks, I have at least 3 WiFi APs immediatley by the test laptop specifically for this test :) Thank you, -- Farhan Khan PGP Fingerprint: B28D 2726 E2BC A97E 3854 5ABE 9A9F 00BC D525 16EE
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