Date: Fri, 6 Jul 2018 17:35:51 -0400 From: Farhan Khan <khanzf@gmail.com> To: Kevin Lo <kevlo@freebsd.org>, avos@freebsd.org, freebsd-wireless@freebsd.org Subject: Where is rtwn(4) scan failing Message-ID: <CAFd4kYCNDTjTbPRxoU_pEbV1sBczhJn6NjfPSgt2c7HsfG3nGQ@mail.gmail.com>
next in thread | raw e-mail | index | archive | help
Hi Kevin, Andriy, et al, As you know, I am working on expanding rtwn(4) to include the rtl8188ee driver. It appears that net80211(4) performs a scan before associating to a BSS, so I am working on scanning. When I run `ifconfig wlan0 scan`, sta_pick_bss() returns immediately without any listed networks suggesting that whatever happens in the driver is failing. It appears that the scanning method begins at rtwn_scan_start(). Using dtrace and manually tracing the source, I identified that the kernel executes the following non-net80211(4) methods: * rtwn_raw_xmit * r92c_fill_tx_desc_raw * r88ee_tx_setup_macid * r88ee_tx_setup_hwseq * rtwn_pci_tx_start_frame * r92ce_copy_tx_desc * r92ce_tx_postsetup * r92ce_dump_tx_desc First, can you please provide a conceptual overview of what is happening in these functions? Second, I am not certain which (or more than one?) are failing to function properly with the new driver. Any ideas? As you know, I am using the Linux rtlwifi code as documentation, but their code is extremely difficult to read. I suspect that FreeBSD's r92c_fill_tx_desc_raw is Linux's rtl92ce_tx_fill_desc, but as I said, the Linux code is extremely difficult to trace through. The rtl8188ee equivalent is rtl88ee_tx_fill_desc. I only noticed 1 difference thus far which I do not understand yet. I suspect somewhere a value is set to 0x1f which should be 0x3f or something of this nature. I was stuck on Rx for around some 6 months and while eventually got it, it would be nice to be a little more efficient with Tx :) Again, any assistance is greatly appreciated. Thank you! -- Farhan Khan PGP Fingerprint: B28D 2726 E2BC A97E 3854 5ABE 9A9F 00BC D525 16EE
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?CAFd4kYCNDTjTbPRxoU_pEbV1sBczhJn6NjfPSgt2c7HsfG3nGQ>