WiFi performance is slow

[Jonas Gamao]

[SRU Justification]

[Impact]

backport-iwlwifi-dkms of latest upstream revision 8324 has no updates for a few months and is becoming a problem when installed against recent kernels >= v5.4. It's reported to have poor network throughput for 7000/8000/9000 series cards.

[Fix]

On Bionic and Eoan, we've skipped module install against kernel >= v5.0 because we have backported drivers for new device models as much as we can. On Focal and on, the in-tree kernel iwlwifi driver is currently much more up to date in comparison to backport-iwlwifi-dkms, so there should be no more reason to install it automatically via modaliases.

So two actions to be taken here:
* to remove modaliases for the dkms package, so that it won't be installed automatically via "3rd party drivers".
* to mark OBSOLETED_BY kernel 5.4.0 and up

[Test Case]

* For new installations, this means backport-iwlwifi-dkms shouldn't be installed automatically even with a PCI id match.
* For existing installations, dkms modules will still be built, but the module installation will be skipped, leaving messages like:

  $ dkms status
  backport-iwlwifi, 8324, 5.4.0-33-generic, x86_64: installed
  (WARNING! Diff between built and installed module!) (WARNING!
  Diff between built and installed module!) (WARNING! Diff
  between built and installed module!) (WARNING! Diff between
  built and installed module!) (WARNING! Diff between built and
  installed module!) (WARNING! Diff between built and installed
  module!)

This can also be tested locally with follow command against packages prebuilt in https://launchpad.net/~vicamo/+archive/ubuntu/ppa-1863583:

  sudo env AUTOPKGTEST_ARTIFACTS=/tmp debian/tests/dkms-autopkgtest

[Regression Potential]
Low. Moving to in-tree drivers instead.

[Other Info]
Focal SRU package for landing in https://launchpad.net/~vicamo/+archive/ubuntu/ppa-1863583 .

========== Original Bug Description ==========

I'm on a 5GHz WiFi network, and my download speeds are slow (roughly 1Mb/s). Tested it with 2.4Ghz connection. For some reason, my upload speeds are fine.

I tested on my other phones, and they aren't experiencing issues (roughly 100Mb/s download). My old laptop, which uses a Broadcom WiFi and only capable of connecting to 2.4GHz, has faster download speeds (roughly 20Mbps). It's also on Focal.

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: backport-iwlwifi-dkms 8324-0ubuntu1
ProcVersionSignature: Ubuntu 5.4.0-18.22-generic 5.4.24
Uname: Linux 5.4.0-18-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
ApportVersion: 2.20.11-0ubuntu21
Architecture: amd64
CurrentDesktop: KDE
Date: Sun Mar 29 10:43:15 2020
InstallationDate: Installed on 2020-01-19 (70 days ago)
InstallationMedia: Kubuntu 19.10 "Eoan Ermine" - Release amd64 (20191017)
PackageArchitecture: all
SourcePackage: backport-iwlwifi-dkms
UpgradeStatus: Upgraded to focal on 2020-03-21 (7 days ago)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Don (mogul345)]

Ended up here via https://askubuntu.com/questions/1230525/ubuntu-20-04-network-performance-extremely-slow

I've got a Dell XPS 13 7390 Developer Edition with the AX200 wifi chipset. Upgraded to 20.04 from 19.10. Post-upgrade, wifi speeds were so slow webpages would not load. After removing the `backport-iwlwifi-dkms` package and rebooting, wifi speeds went back to normal.

[Chris Thompson (chris-thompson)]

Asus VivoBook which uses an Intel Wireless-AC 9462.

Same circumstance and behaviour as reported by Don (above)

[Nikola (nikola303)]

Got here via https://askubuntu.com/questions/1230525/ubuntu-20-04-network-performance-extremely-slow

When I've updated to Ubuntu 20.04 LTS on 02 May 2020, same problem occurred. I've experienced slow wifi performance, much slower than usual. As suggested in duplicate of this bug (https://bugs.launchpad.net/ubuntu/+source/backport-iwlwifi-dkms/+bug/1869588), removing the package backport-iwlwifi-dkms solved the problem.

On Lenovo ThinkPad E580, Network controller: Intel Corporation Dual Band Wireless-AC 3165 Plus Bluetooth

[Daniel Gómez Jurado (gomezjdaniel)]

I am also having slow WiFi performance.. Same as @chris-thompson I have an ASUS VivoBook (S14) which uses an Intel Wireless-AC 9462 and have Ubuntu 20.04 installed.

Remove `backport-iwlwifi-dkms` as suggested doesn't work for me as I don't have that package installed.

[You-Sheng Yang (vicamo)]

@Daniel, please file a new bug so that you can upload logs for your case.

[You-Sheng Yang (vicamo)]

@Jonas, could you paste your `lspci -nnk` output so that we may know the hardware you have? And, does removing backport-iwlwifi-dkms works for you as well?

[Don (mogul345)]

In case it helps - I dug a little deeper and technically, the wifi card in my Dell XPS 13 7390 is a Killer AX1650 card, which is apparently just based on the Intel AX200 chipset. Not sure if it matters, but a small detail.

[You-Sheng Yang (vicamo)]

@Don, please file a new bug as I won't be able to know if yours is completely identical to the reporter's. And, I need you to run apport-collect as well.

[Don (mogul345)]

@You-Sheng,

Done - https://bugs.launchpad.net/ubuntu/+source/backport-iwlwifi-dkms/+bug/1877217

[dou (douphi)]

>02:00.0 Network controller: Intel Corporation Wireless 8265 / 8275 (rev 78)
>firmware=36.77d01142.0

backport-iwlwifi-dkms was completly unstable (drop udp packet bigger than somes bytes )
After removing it worked but with slow speed ..

Without backport-iwlwifi-dkms, wifi was slow on Focal until the last kernel update.
With 5.4.0-31 I recover good performance with over 100Mbs.
Before this kernel it was aroud 3-10Mbs/s
If I remember well I think built-in wifi was slow since my upgrade to focal ( probably starting with 5.4.0-25)

For Focal users , remove backport-iwlwifi-dkms and UPDATE your kernel

There is 3 fix for iwlwifi in https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.4.31
and more pending to get into Focal maybe
https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.4.33
https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.4.36

I have play a lot with driver option to try to recover stability and performance before this kernel update ..
I now use in
/etc/modprobe.d/iwlwifi.conf:
>options iwlwifi debug=1 swcrypto=1 disable_msix=1 disable_11ac=1 disable_11ax=1 power_save=0 bt_coex_active=0

I will check later if I can revert some of this options to default value with 5.4.0-31

Good luck to all

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Tommy Nevtelen (dal)]

Thinkpad X1C6 20.04, 5.4.0-33-generic, had to remove backport-iwlwifi-dkms to get back usable wifi.

This dmesg is after removing the dkms:
$ dmesg |grep -i iwl |grep -v "HW address"
[ 41.918069] iwlwifi 0000:02:00.0: Found debug destination: EXTERNAL_DRAM
[ 41.918071] iwlwifi 0000:02:00.0: Found debug configuration: 0
[ 41.919074] iwlwifi 0000:02:00.0: loaded firmware version 36.77d01142.0 op_mode iwlmvm
[ 42.009330] iwlwifi 0000:02:00.0: Detected Intel(R) Dual Band Wireless AC 8265, REV=0x230
[ 42.019052] iwlwifi 0000:02:00.0: Applying debug destination EXTERNAL_DRAM
[ 42.019365] iwlwifi 0000:02:00.0: Allocated 0x00400000 bytes for firmware monitor.
[ 42.158286] ieee80211 phy0: Selected rate control algorithm 'iwl-mvm-rs'
[ 42.185772] iwlwifi 0000:02:00.0 wlp2s0: renamed from wlan0
[ 44.074867] iwlwifi 0000:02:00.0: Applying debug destination EXTERNAL_DRAM
[ 44.212564] iwlwifi 0000:02:00.0: Applying debug destination EXTERNAL_DRAM
[ 44.280191] iwlwifi 0000:02:00.0: FW already configured (0) - re-configuring

[You-Sheng Yang (vicamo)]

8324-0ubuntu2 is now in groovy with modaliases removed, so it won't be pulled automatically from additional drivers from now on.

[You-Sheng Yang (vicamo)]

https://people.canonical.com/~ubuntu-archive/proposed-migration/groovy/update_excuses.html#backport-iwlwifi-dkms

[Launchpad Janitor (janitor)]

This bug was fixed in the package backport-iwlwifi-dkms - 8324-0ubuntu3

---------------
backport-iwlwifi-dkms (8324-0ubuntu3) groovy; urgency=medium

  * autopkgtest: fix autopkgtest runs on after OBSOLETE_BY=5.4.0.

 -- You-Sheng Yang <email address hidden> Mon, 01 Jun 2020 16:58:28 +0800

[Timo Aaltonen (tjaalton)]

Hello Jonas, or anyone else affected,

Accepted backport-iwlwifi-dkms into focal-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/backport-iwlwifi-dkms/8324-0ubuntu3~20.04.1 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, what testing has been performed on the package and change the tag from verification-needed-focal to verification-done-focal. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-focal. In either case, without details of your testing we will not be able to proceed.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance for helping!

N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days.

[You-Sheng Yang (vicamo)]

verified focal-proposed version 8324-0ubuntu3~20.04.1.

[Launchpad Janitor (janitor)]

This bug was fixed in the package backport-iwlwifi-dkms - 8324-0ubuntu3~20.04.1

---------------
backport-iwlwifi-dkms (8324-0ubuntu3~20.04.1) focal; urgency=medium

  * dkms: stop installing kernel on 5.4 or newer (LP: #1863583)
    - add OBSOLETE_BY=5.4.0
    - fix autopkgtest runs
  * debian: drop modaliases support (LP: #1869587)

 -- You-Sheng Yang <email address hidden> Wed, 03 Jun 2020 11:20:56 +0800

[Brian Murray (brian-murray)]

The verification of the Stable Release Update for backport-iwlwifi-dkms has completed successfully and the package is now being released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regressions.