Intel wifi card + TP-LINK AC1200 rev 1.2 = ???

Intel wifi card + TP-LINK AC1200 rev 1.2 = ???

[Ruben De Smet]

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Hello,

My specs:
=========

Wireless Access Point:
----------------------
TP-LINK AC1200 rev1.2

PC1 (my laptop)
---

- Lenovo Thinkpad X250
- 03:00.0 Network controller: Intel Corporation Wireless 7265 (rev 59)
- Arch Linux (4.6.0-rc6-mainline, I need to update)
- Confirm the bug under 4.5

PC2 (brother's laptop)
---
Acer subnotebook
Intel 7250 (iirc)
Ubuntu 14.04 stock kernel

PC3 (htpc)
---
Zotac HTPC (BI323)
01:00.0 Network controller: Intel Corporation Wireless 3160 (rev 83)
Fedora 23 64 bit with boot-to-Kodi


Newly Ordered PC (cannot confirm yet, could possibly test windows):
----------------
Lenovo Thinkpad T450
Intel 7/8250? Don't know yet, but I know it's Intel again.
Will run Ubuntu 16.04 or 14.04. Not sure yet


They all have in common:
========================
- Linux, Intel wifi card and TP-LINK Archer AC router AC1200 rev 1.2.


The problem(s?):
================

When near the TP-LINK access point, NetworkManager needs reconfirmation
of password. On the htpc, this means loggin in on the console, `nmtui`,
activate connection.

On the computers with DE, this means a dialog box opens asking for a
password, which is already filed. Pressing enter connects to the network.

My laptop, as my brother's, tend to lose the connection now and then.
When I checked `dmesg`, it said to be "lowering the transmission power
as requested by the accesspoint by -xdB" (not those exact words, I can
retrigger the exact error though), before losing the connection some
seconds later.

Other tested (working) configurations:
- TP-LINK Archer C2 (which is without AC iirc)
- Good ol' Linksys WRT
- eduroam at my uni
- any other wifi point I've ever had access to.
- Tested another PC with a lot older (Intel) WiFi card (with AC): same
issue.

Not tested:
- Windows (don't have any Windows pc with those cards near me atm)

I see two options here:
- TP-LINK bug
- Intel iwlwifi bug

Please advice on what I should test, which logs to send, ...

Thank you for reading this WOT!

Ruben De Smet


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Re: Intel wifi card + TP-LINK AC1200 rev 1.2 = ???

[Luca Coelho]

Hi Ruben,

Thanks for the detailed report!

On Mon, 2016-05-23 at 21:08 +0200, Ruben De Smet wrote:
> Hello,
> 
> My specs:
> =========
> 
> Wireless Access Point:
> ----------------------
> TP-LINK AC1200 rev1.2
> 
> PC1 (my laptop)
> ---
> 
> - Lenovo Thinkpad X250
> - 03:00.0 Network controller: Intel Corporation Wireless 7265 (rev
> 59)
> - Arch Linux (4.6.0-rc6-mainline, I need to update)
> - Confirm the bug under 4.5
> 
> PC2 (brother's laptop)
> ---
> Acer subnotebook
> Intel 7250 (iirc)
> Ubuntu 14.04 stock kernel
> 
> PC3 (htpc)
> ---
> Zotac HTPC (BI323)
> 01:00.0 Network controller: Intel Corporation Wireless 3160 (rev 83)
> Fedora 23 64 bit with boot-to-Kodi
> 
> 
> Newly Ordered PC (cannot confirm yet, could possibly test windows):
> ----------------
> Lenovo Thinkpad T450
> Intel 7/8250? Don't know yet, but I know it's Intel again.
> Will run Ubuntu 16.04 or 14.04. Not sure yet
> 
> 
> They all have in common:
> ========================
> - Linux, Intel wifi card and TP-LINK Archer AC router AC1200 rev 1.2.
> 
> 
> The problem(s?):
> ================
> 
> When near the TP-LINK access point, NetworkManager needs
> reconfirmation
> of password. On the htpc, this means loggin in on the console,
> `nmtui`,
> activate connection.
> 
> On the computers with DE, this means a dialog box opens asking for a
> password, which is already filed. Pressing enter connects to the
> network.
> 
> My laptop, as my brother's, tend to lose the connection now and then.
> When I checked `dmesg`, it said to be "lowering the transmission
> power
> as requested by the accesspoint by -xdB" (not those exact words, I
> can
> retrigger the exact error though), before losing the connection some
> seconds later.
> 
> Other tested (working) configurations:
> - TP-LINK Archer C2 (which is without AC iirc)
> - Good ol' Linksys WRT
> - eduroam at my uni
> - any other wifi point I've ever had access to.
> - Tested another PC with a lot older (Intel) WiFi card (with AC):
> same
> issue.
> 
> Not tested:
> - Windows (don't have any Windows pc with those cards near me atm)
> 
> I see two options here:
> - TP-LINK bug
> - Intel iwlwifi bug
> 
> Please advice on what I should test, which logs to send, ...

This sounds like an interoperability issue between your AP (AC1200) and
Intel's NICs.  Did you try any non-Intel NICs with the same AP?

The other AP you mentioned (Archer C2) also supports 802.11ac.  I have
one and haven't had problems with it (I use OpenWRT in it, though).

To go forward on this investigation, could you please create a bugzilla
entry at bugzilla.kernel.org as described in our debugging wikipage[1]?
Please provide at least dmesg and trace-cmd logs of the failing case to
start with.

Additionally, you could capture sniffer logs with one of your devices
while the other is having trouble so we can see what is going on.  Let
us know if you need help with that.

[1] https://wireless.wiki.kernel.org/en/users/drivers/iwlwifi/debugging

--
Cheers,
Luca.
> 

Re: Intel wifi card + TP-LINK AC1200 rev 1.2 = ???

[Ruben De Smet]

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Apparently, this was still in my drafts. Sorry for the delay. I've been
away from home for a couple of weeks, today I'm home for one day, so
I've made the files you suggested.

On 05/24/2016 07:52 AM, Luca Coelho wrote:
> This sounds like an interoperability issue between your AP (AC1200) and
> Intel's NICs.  Did you try any non-Intel NICs with the same AP?

I have a Broadcom card that I *think* I used it with. But that's a while
ago; I blew that motherboard.

We have another Broadcom in an HP Pavillion, running Ubuntu 14.04. This
one never has problems (on the WiFi. Everything else on that PC is
garbage though. That's why we ordered the T450...)

> 
> The other AP you mentioned (Archer C2) also supports 802.11ac.  I have
> one and haven't had problems with it (I use OpenWRT in it, though).

Oh, okay, was not sure. Anyhow, I don't have any problems with the C2
neither, with stock firmware.

> 
> To go forward on this investigation, could you please create a bugzilla
> entry at bugzilla.kernel.org as described in our debugging wikipage[1]?
> Please provide at least dmesg and trace-cmd logs of the failing case to
> start with.

https://bugzilla.kernel.org/show_bug.cgi?id=120471

> 
> Additionally, you could capture sniffer logs with one of your devices
> while the other is having trouble so we can see what is going on.  Let
> us know if you need help with that.

Well... At this point, I do not think I have a device capable of
promiscous mode that's not Intel (and so, failing).


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