P2P GO mysteriously goes offline
blairmburtan at gmail.com
Fri Apr 19 14:23:46 PDT 2019
I've been trying to track down a problem for about a month now and I'm
hoping somebody here can shed some light on this. Bear with me and
please read the description of the problem carefully.
I'm using WPA Supplicant 2.7 in conjunction with Texas Instruments
wl12xx drivers on a TiWi-BLE device. I have the most recent firmware
for this device. I'm using the procedure as described by Texas
Instruments in this page:
I want to set up the system in what TI refers to as multi-role which
means a P2P GO along with a traditional Station role. This works
under the following conditions:
1) If there are no network blocks in the wpa_supplicant configuration
file or if the network blocks have disabled=1 in all of them.
2) If there are one or more network blocks in the file and one of the
routers specified can be reached.
However, if there are one or more network blocks in the file and none
of the routers are available, the P2P GO SSID will be visible for a
short period of time e.g. two minutes, ten minutes, and then the SSID
mysteriously vanishes even if something was connected. When it does
vanish, there is no notification in the verbose wpa_supplicant debug
output nor is there any warning message from the driver.
Digging deeper, I'm running Linux 4.1.15 and I've tried this in a
Yocto build as well as a Debian build. I've posted this question to
the TI forum and their response is "This device is no longer
supported." Wunderbar. Part of me was thinking that there's a driver
problem in wlcore and/or wl12xx which show a few changes since April
2015 in the Linux repository that might be relevant. This has lead me
to a fruitless effort to use backports to get current drivers.
Today, I wanted to document my tests before posting here and I was
working with the Debian distro. Oddly enough, when there was any
enabled but not reachable network block, the P2P GO SSID would never
become visible to another computer. Texas Instruments mentioned
something to the effect that the wl1271 device has a limitation
regarding the frequency in that you can't run P2P on the same
frequency as regular Station mode. So I edited the network block to
allow any frequency except channel 11 and ran P2P GO on channel 11.
That didn't help but in reading the docs for wpa_supplicant.conf I
read about ap_scan and that mode 0 would allow the driver to do
scanning so I added this. Now, the P2P GO SSID stays up.
So, my question to the gurus out there is why would allowing
wpa_supplicant to initiate scanning bork the P2P GO system? Did I
uncover an obscure bug here?
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