Re: [linuxwifi] Slow performance (~30mbps) with Intel 9260 (and 8265, 3168) using 5G

From: Luciano Coelho <luciano.coelho@intel.com>
To: Qu Wenruo <quwenruo.btrfs@gmx.com>,
	linuxwifi@intel.com,
	linux-wireless <linux-wireless@vger.kernel.org>
Subject: Re: [linuxwifi] Slow performance (~30mbps) with Intel 9260 (and 8265, 3168) using 5G
Date: Mon, 09 Sep 2019 09:18:59 +0300	[thread overview]
Message-ID: <10f877f29750ceb357fa5b54bf07122c658270ca.camel@intel.com> (raw)
In-Reply-To: <42bd356c-6c59-79dc-bb37-5bc36d07a9af@gmx.com>

On Mon, 2019-09-09 at 14:09 +0800, Qu Wenruo wrote:
> 
> On 2019/9/9 下午2:00, Luciano Coelho wrote:
> > Hi,
> > 
> > On Sun, 2019-09-08 at 06:45 +0800, Qu Wenruo wrote:
> > > Hi,
> > > 
> [...]
> > > Any ideas how this could happen to 3 different intel cards on two
> > > different systems? (Although all running the same Arch kernel and latest
> > > firmware)
> > 
> > This really must be an environment issue.  You are describing the same
> > problem with different NICs (which mean different FWs are being used)
> > and the same problem on Windows (which means different driver version
> > being used), so it's not a new bug in either the firmware or the
> > driver.
> 
> You're completely right. I have reset and upgraded my router (an MT7621
> based router with OpenWRT) to latest OpenWRT, then the problem just went
> away.

Great!

> It looks like, under the original environment, it's the Android phone
> doing something strange.

It's hard to tell, because the characteristics of the WiFi on your
Android phone are very different from those on your laptop.

> > Was it working properly before? Did it start happening only when you
> > changed the NIC (even though you changed it back and it remained not
> > working)? What else changed?
> 
> Nothing really, so I may hit something wrong with the NIC of the router,
> not all these NICs.

There was probably an upgrade of OpenWRT that started causing the
issue.  Hard to say.

> > I can't see anything hinting any issues in dmesg.  Also, I'm a bit
> > confused about the "5G" you mention.  Does that mean that the AP is
> > connected to the internet via 5G?
> 
> Sorry for the confusion, I mean 5Ghz.

Ah, I should have guessed, of course.  It's just that the word 5G has a
totally different meaning, hardcoded in my head, so I got confused. ;)

> All tests are done in 5GHz freq (802.11ac), and iperf server is
> connected by RJ45 (1Gbps) and iperf client is through wifi.
> 
> Anyway, after resetting the router, it's now back to the ~300 mpbs range.

That's great to hear! Let us know if you encounter any further issues.

--
Cheers,
Luca.