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.

 

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?
2) Why does the wifi interface name change from wlan0 to wlx801f02a693cf 
upon connmanctl connection?
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' 

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?

 

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.

Debug info:

*uname* 

*Linux arm 4.4.9-ti-r25 #1 SMP Fri May 6 10:28:56 UTC 2016 armv7l armv7l 
armv7l GNU/Linux*


*lsusb*


*Bus 001 Device 003: ID 7392:7811 Edimax Technology Co., Ltd EW-7811Un 
802.11n Wireless Adapter [Realtek RTL8188CUS]*
*Bus 001 Device 002: ID 2109:2811 VIA Labs, Inc. Hub*
*Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub*


*lsmod*

*Module                  Size  Used by*
*ccm                     6653  2*
*arc4                    2019  2*
*rtl8192cu              52212  0*
*rtl_usb                 8788  1 rtl8192cu*
*rtl8192c_common        37683  1 rtl8192cu*
*rtlwifi                54043  3 rtl_usb,rtl8192c_common,rtl8192cu*
*mac80211              484877  3 rtl_usb,rtlwifi,rtl8192cu*
*cfg80211              417677  2 mac80211,rtlwifi*
*usb_f_ecm               9400  1*
*g_ether                 4976  0*
*usb_f_rndis            22191  2 g_ether*
*u_ether                11917  3 usb_f_ecm,usb_f_rndis,g_ether*
*libcomposite           43461  3 usb_f_ecm,usb_f_rndis,g_ether*
*pruss_intc              3592  0*
*snd_soc_simple_card     8385  0*
*pru_rproc              11295  0*
*omap_rng                4423  0*
*omap_sham              21629  0*
*pruss                  11615  1 pru_rproc*
*omap_aes_driver        18917  0*
*rng_core                7471  1 omap_rng*
*bluetooth             417817  2*
*rfkill                 18226  5 cfg80211,bluetooth*
*snd_soc_davinci_mcasp    16596  2*
*snd_soc_edma            1290  1 snd_soc_davinci_mcasp*
*snd_soc_omap            3058  1 snd_soc_davinci_mcasp*
*spi_omap2_mcspi        10764  0*
*snd_soc_hdmi_codec      5842  1*
*snd_soc_core          155592  5 
snd_soc_hdmi_codec,snd_soc_davinci_mcasp,snd_soc_edma,snd_soc_omap,snd_soc_simple_card*
*snd_pcm_dmaengine       5209  2 snd_soc_core,snd_soc_omap*
*snd_pcm                82689  5 
snd_soc_hdmi_codec,snd_soc_davinci_mcasp,snd_soc_core,snd_soc_omap,snd_pcm_dmaengine*
*snd_timer              19720  1 snd_pcm*
*snd                    59559  3 snd_soc_core,snd_timer,snd_pcm*
*soundcore               7601  1 snd*
*evdev                  10695  2*
*uio_pdrv_genirq         3539  0*
*uio                     8822  1 uio_pdrv_genirq*
*tilcdc                 26364  0*
*tda998x                12754  0*

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