On Mon, May 23, 2016 at 6:23 AM, Marcos Scriven <[email protected]> wrote:
> I'm trying to get an Edimax EW-7811UN working on my BBB rev A5C, which is > listed on the Beagleboard wiki as working: > http://www.elinux.org/Beagleboard:BeagleBoneBlack#WIFI_Adapters > > Frustratingly, it sort of works for a few minutes (I get an IP, and can > log in), but then seems to stop. I see no logs to suggest the dongle has > disconnected, or any networking errors logs. I'm sure there's nothing wrong > physically with the dongle, as I've tried two of them, both of which work > fine in my Raspberry Pi for long periods > > There appears to be three aspects here: > > 1) Driver issues - there seems to be the rtl8192cu in mainline kernel, and > various dynamic kernel modules (such as > https://github.com/pvaret/rtl8192cu-fixes) that apparently exist due to > the drivers being flaky. I know the RaspberryPi kernel uses a very similar > fork of the open source 'fixed' module, but is instead compiled into the > kernel RPi uses in its distributions > > > > 2) Kernel version - related to the driver issues, but so far as I know the > rtl8192cu driver in mainline has had some improvements in the 4.4 kernel. > I've tried both at 4.1.x kernel (from Elias's 'Kamikazee' fork or Robert's > image build), and Robert's own latest 4.4.9-ti-r25 kernel (of the 2GB > ubuntu flasher variety). The problem is Elias's build is convenient as it > has everything setup for the Replicape, but is an older kernel. > > He will move to v4.4.x when he's ready.. Elias's does a lot of work to make sure his Cape's works, so he will move when he's ready.. > > > 3) Power - this is the most opaque issue to me. I've tried both with and > without a powered USB hub, but I've no way of telling if the USB hub is > doing its job, and supplying power to the Wifi dongle directly, rather than > asking the BBB host for it. I'm using this 'Amazon Basics' one, which > appears to be a rebranded VIA labs model): > https://www.amazon.co.uk/AmazonBasics-4-Port-USB-3-0-Plug/dp/B00E0NH7DQ/ref=sr_1_9?s=electronics&ie=UTF8&qid=1464001382&sr=1-9&keywords=amazon+usb+hub > > > Questions: > > 1) For an RTL8188CUS based chip, on a >= 4.4.9 kernel, am I best off using > the builtin driver, or compiling the open source one? > > It depends, the RTL8188's have been fussy, use either or, linux-headers-`uname -r` are in the repo for you to use.. > 2) Why does the wifi interface name change from wlan0 to wlx801f02a693cf > upon connmanctl connection? > > systemd does that: https://www.freedesktop.org/wiki/Software/systemd/PredictableNetworkInterfaceNames/ > 3) Why do I need to 'disable wifi' in connmanctl before enabling it a > second time, for it to see 'wifi' as an available 'technology' > > Because i have "wifi tether" enabled.. connmanctl> tether wifi off > 4) What's my next step if things like 'dmesg' aren't showing any issues? > (I'm not seeing the USB device repeatedly being disconnected/connected for > instance, or repeated DHCP reqs or anything. In fact, between the device > having a connection and not, I sometimes see not further dmesg logs at all. > > 5) If the BBB is powered via the mini-USB port, but I'm using a powered > hub, is it still a problem for the BBB? > > 6) How can I tell for sure the powered hub is supplying power to the > dongle instead of the BBB? > > 7) Eventually I'm going to attached the Replicape, which is itself will be > powered by a computer PSU, and will actually provide the BBB with 5V > through the cape. What would the USB power situation be then? Would the BBB > host then be able to provide enough power? > > Until you try powering the device via 5VDC power, there's not much to comment on above.. > > > It's the combination of driver vs open source dynamic module, kernel > version, and opaque (to me) USB power issues that I think is making this > Wifi connection flakiness frustrating. > Personally, it smells like a power problem.. Regards, -- Robert Nelson https://rcn-ee.com/ -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/CAOCHtYiWx71Fj%2BdROTEaUr%3DbQUqAK8mNH4KuZP%3DCBftSuKjFuQ%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
