8086:08b2 [Lenovo ThinkPad T440s] Power management causes Intel wifi 7260 slowness

[Francois Thirioux]

With power management on, download speed reaches an upper limit 400 kB/s instead of the normal 1500 kB/s I get with some other PC connected to my network. The speed often slows down very very low, especially when I'm far away from my AP. Removing N mode does not solve the issue.

03:00.0 Network controller [0280]: Intel Corporation Wireless 7260 [8086:08b2] (rev 83)
 Subsystem: Intel Corporation Dual Band Wireless-AC 7260 [8086:c270]

This is a regression in Trusty update going from linux-firmware 1.127 to 1.127.10. As per https://launchpad.net/ubuntu/+archive/primary/+files/linux-firmware_1.127.tar.gz this is how 1.127 only included:
/linux-firmware/iwlwifi-7260-7.ucode
/linux-firmware/iwlwifi-7260-8.ucode

However, as per https://launchpad.net/ubuntu/+archive/primary/+files/linux-firmware_1.127.10.tar.gz it includes:
/linux-firmware/iwlwifi-7260-8.ucode
/linux-firmware/iwlwifi-7260-9.ucode

WORKAROUND: Remove wireless interface's power management via Powertop
or
WORKAROUND: Revert to previous iwlwifi-7260-8.ucode (remove the -9 version from /lib/firmware)
WORKAROUND: Use latest Intel upstream firmware iwlwifi-7260-ucode-23.10.10.0 with 3.17+ kernels
WORKAROUND : use the default (25.222.9.0) firmware and disable uAPSD (see message #64)

---
ApportVersion: 2.14.1-0ubuntu3
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC1: ft 1884 F.... pulseaudio
 /dev/snd/controlC0: ft 1884 F.... pulseaudio
DistroRelease: Ubuntu 14.04
HibernationDevice: RESUME=UUID=54b265b9-4433-42d4-8d0f-fac028ee7030
InstallationDate: Installed on 2014-03-05 (46 days ago)
InstallationMedia: Ubuntu-GNOME 14.04 "Trusty Tahr" - Alpha amd64 (20140226)
Lsusb:
 Bus 001 Device 002: ID 8087:8000 Intel Corp.
 Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
 Bus 003 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
 Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
MachineType: LENOVO 20AQCTO1WW
Package: linux (not installed)
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 LANG=fr_FR.UTF-8
 SHELL=/bin/bash
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.13.0-24-generic.efi.signed root=UUID=b1cbc034-b66f-4f6c-9d61-507b8cb23ffe ro quiet
ProcVersionSignature: Ubuntu 3.13.0-24.46-generic 3.13.9
PulseList:
 Error: command ['pacmd', 'list'] failed with exit code 1: Home directory not accessible: Permission denied
 No PulseAudio daemon running, or not running as session daemon.
RelatedPackageVersions:
 linux-restricted-modules-3.13.0-24-generic N/A
 linux-backports-modules-3.13.0-24-generic N/A
 linux-firmware 1.127
RfKill:
 0: phy0: Wireless LAN
  Soft blocked: no
  Hard blocked: no
Tags: trusty
Uname: Linux 3.13.0-24-generic x86_64
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups:

_MarkForUpload: True
dmi.bios.date: 03/28/2014
dmi.bios.vendor: LENOVO
dmi.bios.version: GJET75WW (2.25 )
dmi.board.asset.tag: Not Available
dmi.board.name: 20AQCTO1WW
dmi.board.vendor: LENOVO
dmi.board.version: 0B98405 STD
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Not Available
dmi.modalias: dmi:bvnLENOVO:bvrGJET75WW(2.25):bd03/28/2014:svnLENOVO:pn20AQCTO1WW:pvrThinkPadT440s:rvnLENOVO:rn20AQCTO1WW:rvr0B98405STD:cvnLENOVO:ct10:cvrNotAvailable:
dmi.product.name: 20AQCTO1WW
dmi.product.version: ThinkPad T440s
dmi.sys.vendor: LENOVO

[Ubuntu Foundations Team Bug Bot (crichton)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. It seems that your bug report is not filed about a specific source package though, rather it is just filed against Ubuntu in general. It is important that bug reports be filed about source packages so that people interested in the package can find the bugs about it. You can find some hints about determining what package your bug might be about at https://wiki.ubuntu.com/Bugs/FindRightPackage. You might also ask for help in the #ubuntu-bugs irc channel on Freenode.

To change the source package that this bug is filed about visit https://bugs.launchpad.net/ubuntu/+bug/1289961/+editstatus and add the package name in the text box next to the word Package.

[This is an automated message. I apologize if it reached you inappropriately; please just reply to this message indicating so.]

[Joseph Salisbury (jsalisbury)]

Would it be possible for you to test the latest upstream kernel? Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Please test the latest v3.14 kernel[0].

If this bug is fixed in the mainline kernel, please add the following tag 'kernel-fixed-upstream'.

If the mainline kernel does not fix this bug, please add the tag: 'kernel-bug-exists-upstream'.

If you are unable to test the mainline kernel, for example it will not boot, please add the tag: 'kernel-unable-to-test-upstream'.
Once testing of the upstream kernel is complete, please mark this bug as "Confirmed".

Thanks in advance.

[0] http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.14-rc6-trusty/

[Francois Thirioux (fthx)]

Ok.

The latest 3.14 kernel speeds up my wifi connection but does not reach the best value :

downloading far away from my router a file on a local-network hard drive :
- 3.13 with wifi power management : 60 ko/s
- 3.13 without PM : 360 ko/s
- 3.14 without PM : 500 ko/s
- saucy kernel on X220 (6230 intel wifi card) : >950 ko/s

So it seems to me that enabling PM makes wifi speed much better but by far not as it should be.

Thanks.

[Francois Thirioux (fthx)]

I add that the connection runs at max speed at the beginning of data transfer. After some dozens of seconds of data transfer the speed slows down (e.g. where I am connected at the moment, with PM=on, it went from 1200 ko/s to 360 ko/s when running internet speed tests).

[Joseph Salisbury (jsalisbury)]

Did this issue also happen in prior releases, or is this new in Trusty?

[Francois Thirioux (fthx)]

I did not test another release on this laptop, only Trusty with 3.13 and 3.14rc6 kernels. A lot of people in forums complain about 7260 wifi card (disconnections, slowness, choppy connection, bad range...), not only using Linux. Maybe is it just firmware-related ?

[korak (korak7)]

I can confirm this bug. I've got a Lenovo Yoga 2 Pro.

Ubuntu 12.04.4
3.11.0-15-generic
iwlwifi
firmware 22.0.7.0
power management enabled: 90 Mbps (that is my max possible internet speed, haven't tried any local file transfers tough maybe it is even faster)
power management disabled: 90 Mbps
--> PM does not seem to have an effect on the wifi speed but the connection isn't stable at all. It reconnect aproximately ever 2 minutes.

Ubuntu 14.04
3.13.0.-17-generic
iwlwifi
firmware 22.24.8.0
power management enabled: 4-24 Mbps (<- signal strength changes)
power management disabled: 32 Mbps (<- signal strength seems to be always good)
--> Here I don't have any disconnects and PM has an influence but additionally the speed is generally a lot slower.

3.14.0-031400rc6-generic
firmware 22.24.8.0
--> I cannot notice different behavior compared to previous kernel, at least no noteworthy differences

[Francois Thirioux (fthx)]

Still occurs running new 3.13.7 ubuntu kernel (containing some iwlwifi/mac stuff).

[Ray-Ven (ray-ven)]

same same on lenovo thinkpad yoga. Less (maybe no) problems when turning wifi-router to g-only mode (no n-mode).

[Ray-Ven (ray-ven)]

kubuntu trusty, linux 3.13.0-19-generic

[Francois Thirioux (fthx)]

I kept BGN mode for my router.

With latest :
3.13.0-20-generic #42-Ubuntu
I get max speed with PM off (somewhat far from my router) and half of it when PM is on. So it is much better but the title of this bug remains open.
The iwlwifi/mac changes in 3.13.7 seem to partially work ?

I noticed that my other laptops (1 with saucy, 1 with precise -- saucy or raring kernel--) do *not* have PM turned on, without any tweak. Running trusty, PM is by default turned on.

[Joel Schopp (joel-schopp)]

Also worth noting this related bug with the same wifi adapter:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1289961

[Joel Schopp (joel-schopp)]

Managed to get the wifi stable by disabling n and power savings.
sudo vi /etc/modprobe.d/iwlwifi-disable11n.conf
Add this line: options iwlwifi 11n_disable=1
powertop to set Wireless Power Saving for interface wlan0 off

uname -a
Linux p55t 3.13.0-20-generic #42-Ubuntu SMP Fri Mar 28 09:56:33 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux

Some info from lspci (after the above config changes):

02:00.0 Network controller: Intel Corporation Wireless 7260 (rev 73)
 Subsystem: Intel Corporation Wireless-N 7260
 Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx+
 Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
 Latency: 0, Cache Line Size: 64 bytes
 Interrupt: pin A routed to IRQ 59
 Region 0: Memory at f7d00000 (64-bit, non-prefetchable) [size=8K]
 Capabilities: [c8] Power Management version 3
  Flags: PMEClk- DSI+ D1- D2- AuxCurrent=0mA PME(D0+,D1-,D2-,D3hot+,D3cold+)
  Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME-
 Capabilities: [d0] MSI: Enable+ Count=1/1 Maskable- 64bit+
  Address: 00000000fee0800c Data: 41b1
 Capabilities: [40] Express (v2) Endpoint, MSI 00
  DevCap: MaxPayload 128 bytes, PhantFunc 0, Latency L0s <512ns, L1 unlimited
   ExtTag- AttnBtn- AttnInd- PwrInd- RBE+ FLReset+
  DevCtl: Report errors: Correctable- Non-Fatal- Fatal- Unsupported-
   RlxdOrd- ExtTag- PhantFunc- AuxPwr+ NoSnoop+ FLReset-
   MaxPayload 128 bytes, MaxReadReq 128 bytes
  DevSta: CorrErr- UncorrErr- FatalErr- UnsuppReq- AuxPwr+ TransPend-
  LnkCap: Port #0, Speed 2.5GT/s, Width x1, ASPM L0s L1, Exit Latency L0s <4us, L1 <32us
   ClockPM+ Surprise- LLActRep- BwNot-
  LnkCtl: ASPM Disabled; RCB 64 bytes Disabled- CommClk+
   ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt-
  LnkSta: Speed 2.5GT/s, Width x1, TrErr- Train- SlotClk+ DLActive- BWMgmt- ABWMgmt-
  DevCap2: Completion Timeout: Range B, TimeoutDis+, LTR+, OBFF Via WAKE#
  DevCtl2: Completion Timeout: 50us to 50ms, TimeoutDis-, LTR+, OBFF Disabled
  LnkCtl2: Target Link Speed: 2.5GT/s, EnterCompliance- SpeedDis-
    Transmit Margin: Normal Operating Range, EnterModifiedCompliance- ComplianceSOS-
    Compliance De-emphasis: -6dB
  LnkSta2: Current De-emphasis Level: -3.5dB, EqualizationComplete-, EqualizationPhase1-
    EqualizationPhase2-, EqualizationPhase3-, LinkEqualizationRequest-
 Capabilities: [100 v1] Advanced Error Reporting
  UESta: DLP- SDES- TLP- FCP- CmpltTO- CmpltAbrt- UnxCmplt- RxOF- MalfTLP- ECRC- UnsupReq- ACSViol-
  UEMsk: DLP- SDES- TLP- FCP- CmpltTO- CmpltAbrt- UnxCmplt- RxOF- MalfTLP- ECRC- UnsupReq- ACSViol-
  UESvrt: DLP+ SDES+ TLP- FCP+ CmpltTO- CmpltAbrt- UnxCmplt- RxOF+ MalfTLP+ ECRC- UnsupReq- ACSViol-
  CESta: RxErr- BadTLP- BadDLLP- Rollover- Timeout- NonFatalErr-
  CEMsk: RxErr- BadTLP- BadDLLP- Rollover- Timeout- NonFatalErr+
  AERCap: First Error Pointer: 00, GenCap- CGenEn- ChkCap- ChkEn-
 Capabilities: [140 v1] Device Serial Number fc-f8-ae-ff-ff-58-32-b1
 Capabilities: [14c v1] Latency Tolerance Reporting
  Max snoop latency: 3145728ns
  Max no snoop latency: 3145728ns
 Capabilities: [154 v1] Vendor Specific Information: ID=cafe Rev=1 Len=014 <?>
 Kernel driver in ...

[Thomas Vachon (vachon)]

I also have this on the latest Trusty nightly. Turning off PM fixes it.

I have a 50/10Mbit connection here, and I start at 20Mbit and quickly fall all the way to ~2Mbit. This is over multiple sequential download (e.g apt-get upgrade). This is even worse if you are connected over a mobile hotspot, for instance an iPhone personal hostspot. I get one webpage to load in that case, but the DNS packets and MBDN end up putting the link into a very slow state, ~20Kbps or less.

Turning off PM and blacklisting it, I can constantly pull the 50/10. I have yet to test the hostspot fix, I will be able to tomorrow.

Also, I noticed that with PM on (and even off but less so) , there was very very high excessive TX retry (48k in 20 minutes) and the computer is bouncing between two channels broadcasting the same BSSID (Apple Airport Extreme multi-ap network),

[Thomas Vachon (vachon)]

Confirmed, it also fixes connecting the iPhone/iPad hotspot. Having dealt with MAcs in WLAN enterprise networks before, I know when they start flapping in and out of powersave, things break, so this makese sense if the laptop was triggering that conditition through its powersave issue

[Joel Schopp (joel-schopp)]

This seems to be fixed now. I am running with n mode and power saving with no problems as of latest 14.04, more specifically:

jschopp@p55t:~$ uname -a
Linux p55t 3.13.0-24-generic #46-Ubuntu SMP Thu Apr 10 19:11:08 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux

[penalvch (penalvch)]

Francois Thirioux, could you please execute the following at a terminal:
apport-collect 1289961

[Francois Thirioux (fthx)]

Apport collect to follow.

I did 8 measures of wifi speed (quite far from my router 2.4 GHz WPA2 AES) with and without PM. I removed the best and the worst :
mean PM on : 418 ko/s
mean PM off : 562 ko/s

Sure it is much better than before (when I opened this bug) but not as much as it should. Additionnally, there is still a speed issue, PM on or off, since I get ~900 ko/s with another laptop running Intel 6235 card an using the same number of antennas.

[Francois Thirioux (fthx)]

apport information

[Francois Thirioux (fthx)]

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[Francois Thirioux (fthx)]

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[Francois Thirioux (fthx)]

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[Francois Thirioux (fthx)]

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[Francois Thirioux (fthx)]

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[Francois Thirioux (fthx)]

apport information

[Francois Thirioux (fthx)]

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[Francois Thirioux (fthx)]

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[Francois Thirioux (fthx)]

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[Francois Thirioux (fthx)]

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[Francois Thirioux (fthx)]

apport information

[penalvch (penalvch)]

Francois Thirioux, could you please test the latest mainline kernel via http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.15-rc2-trusty/ and advise to the results?

[Francois Thirioux (fthx)]

no changes with 3.15 rc2.
+1 to Joel's message.

[Thomas M Steenholdt (tmus)]

Lots of talk about bandwidth, but (IMHO) at least as interesting is ping times (because the results are instantly visible):

I'm on a ThinkPad T431s with an "Intel Corporation Centrino Advanced-N 6235 (rev 24)"

3.13.0-24-generic without PM (pinging my AP):

$ ping -c 5 192.168.8.2
PING 192.168.8.2 (192.168.8.2) 56(84) bytes of data.
64 bytes from 192.168.8.2: icmp_seq=1 ttl=64 time=0.882 ms
64 bytes from 192.168.8.2: icmp_seq=2 ttl=64 time=0.948 ms
64 bytes from 192.168.8.2: icmp_seq=3 ttl=64 time=0.960 ms
64 bytes from 192.168.8.2: icmp_seq=4 ttl=64 time=0.768 ms
64 bytes from 192.168.8.2: icmp_seq=5 ttl=64 time=0.848 ms

--- 192.168.8.2 ping statistics ---
5 packets transmitted, 5 received, 0% packet loss, time 4002ms
rtt min/avg/max/mdev = 0.768/0.881/0.960/0.072 ms

3.13.0-24-generic with PM (pinging my AP):

$ ping -c 5 192.168.8.2
PING 192.168.8.2 (192.168.8.2) 56(84) bytes of data.
64 bytes from 192.168.8.2: icmp_seq=1 ttl=64 time=96.9 ms
64 bytes from 192.168.8.2: icmp_seq=2 ttl=64 time=17.2 ms
64 bytes from 192.168.8.2: icmp_seq=3 ttl=64 time=39.4 ms
64 bytes from 192.168.8.2: icmp_seq=4 ttl=64 time=61.9 ms
64 bytes from 192.168.8.2: icmp_seq=5 ttl=64 time=84.7 ms

--- 192.168.8.2 ping statistics ---
5 packets transmitted, 5 received, 0% packet loss, time 4005ms
rtt min/avg/max/mdev = 17.298/60.076/96.938/29.065 ms

[penalvch (penalvch)]

Francois Thirioux, did this problem not occur in a release prior to Trusty?

Thomas M Steenholdt, thank you for your comment. So your hardware and problem may be tracked, could you please file a new report with Ubuntu by executing the following in a terminal while booted into a Ubuntu repository kernel (not a mainline one) via:
ubuntu-bug linux

For more on this, please read the official Ubuntu documentation:
Ubuntu Bug Control and Ubuntu Bug Squad: https://wiki.ubuntu.com/Bugs/BestPractices#X.2BAC8-Reporting.Focus_on_One_Issue
Ubuntu Kernel Team: https://wiki.ubuntu.com/KernelTeam/KernelTeamBugPolicies#Filing_Kernel_Bug_reports
Ubuntu Community: https://help.ubuntu.com/community/ReportingBugs#Bug_reporting_etiquette

When opening up the new report, please feel free to subscribe me to it.

Thank you for your understanding.

Helpful bug reporting tips:
https://wiki.ubuntu.com/ReportingBugs

[Francois Thirioux (fthx)]

(By far, I do not get any big difference between ping with and without PM. Near by my router, 2.2 ms to 2.5 ms.)

I do not know if this problem occurs in prior releases. Never tested.

[penalvch (penalvch)]

Francois Thirioux, for regression testing purposes, could you please test for this in 12.04.0 via http://old-releases.ubuntu.com/releases/12.04.0/ and advise if this is reproducible?

[Ray-Ven (ray-ven)]

I've been losing connection with 3.13.0-24-generic with high download rates. After a few "fn"+"Wireless Button" actions and reconnectings it seems to be stable. strange

[penalvch (penalvch)]

Ray-Ven, thank you for your comment. So your hardware and problem may be tracked, could you please file a new report with Ubuntu by executing the following in a terminal while booted into a Ubuntu repository kernel (not a mainline one) via:
ubuntu-bug linux

For more on this, please read the official Ubuntu documentation:
Ubuntu Bug Control and Ubuntu Bug Squad: https://wiki.ubuntu.com/Bugs/BestPractices#X.2BAC8-Reporting.Focus_on_One_Issue
Ubuntu Kernel Team: https://wiki.ubuntu.com/KernelTeam/KernelTeamBugPolicies#Filing_Kernel_Bug_reports
Ubuntu Community: https://help.ubuntu.com/community/ReportingBugs#Bug_reporting_etiquette

When opening up the new report, please feel free to subscribe me to it.

Thank you for your understanding.

Helpful bug reporting tips:
https://wiki.ubuntu.com/ReportingBugs

[Francois Thirioux (fthx)]

A revert to v7 Intel driver has been committed in linux-firmware 127.2 , so I'll wait...

[Thomas Vachon (vachon)]

I can confirm on the latest released packages its still a problem. A package actually rolled back my hook blacklist and now finally my wifi is stable again

[penalvch (penalvch)]

Thomas Vachon, please again see https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1289961/comments/34 .

[Thomas Vachon (vachon)]

Chris,

I didn't have this chipset prior to Trusty. Do you want PM on or off for that ubuntu-bug run

[Thomas Vachon (vachon)]

Christopeher,

Run with PM on. https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1319791

[Launchpad Janitor (janitor)]

[Expired for linux (Ubuntu) because there has been no activity for 60 days.]

[OP (opryymak)]

Confirming the same issue on Ubuntu 14.04.1 LTS with the most recent updates at the moment of the comment.

Turning off wireless power management works as a temporary fix.

[penalvch (penalvch)]

OP, thank you for your comment. Unfortunately, this bug report is not scoped to you, or your problem. So your hardware and problem may be tracked, could you please file a new report with Ubuntu by executing the following in a terminal while booted into the default Ubuntu kernel (not a mainline one) via:
ubuntu-bug linux

For more on this, please read the official Ubuntu documentation:
Ubuntu Bug Control and Ubuntu Bug Squad: https://wiki.ubuntu.com/Bugs/BestPractices#X.2BAC8-Reporting.Focus_on_One_Issue
Ubuntu Kernel Team: https://wiki.ubuntu.com/KernelTeam/KernelTeamBugPolicies#Filing_Kernel_Bug_reports
Ubuntu Community: https://help.ubuntu.com/community/ReportingBugs#Bug_reporting_etiquette

When opening up the new report, please feel free to subscribe me to it.

As well, please do not announce in this report you created a new bug report.

Thank you for your understanding.

Helpful bug reporting tips:
https://wiki.ubuntu.com/ReportingBugs

[Launchpad Janitor (janitor)]

[Expired for linux (Ubuntu) because there has been no activity for 60 days.]

[Francois Thirioux (fthx)]

I do reopen this bug as it is still alive.

I've just installed a wifi repeater, N mode, good connection to router and signal emitting strength.

Tests with bandwith tests and dowloads of big files :

- windows 8 with uapsd off : 1,5 Mo/s

- ubuntu 14.10 kernel 3.16.0-25 or 26, driver 25.222.9.0 (native linux-firmware) or 25.228.9.0 (intel's iwlwifi latest) :
------ with power management : at the beginning of some dowloads (just after the end of the boot), 1 Mo/s and after a dozen of seconds 250 ko/s (not increasing after some time)
------ without power management (off via powertop) : 1,5 Mo/s

SO : there is still a huge rate issue.

[Brad Figg (brad-figg)]

This change was made by a bot.

[penalvch (penalvch)]

Francois Thirioux, for regression testing purposes, could you please test for this in 12.04.0 (not 12.04.3 or some other variant) via http://old-releases.ubuntu.com/releases/12.04.0/ and advise if this is reproducible?

[Francois Thirioux (fthx)]

I do not have the time to do that now but i'll try in one week. Does 12.04.0 contain the 7260 firmware ? If not, what firmware should I use for ?

I can quickly test some firmware with Utopic ?

[Francois Thirioux (fthx)]

I quickly tested the dowload speed with :

kernel 3.18 rc7 from Ubuntu's kernel archive
iwlwifi 23.10.10 (for kernel>=3.17) firmware
power management not tweaked, i.e. it means ON

I've got NO speed issues with this config. Hope it helps.

[penalvch (penalvch)]

Francois Thirioux, is this problem reproducible if you use the firmware that came by default with Ubuntu, and the latest mainline kernel 3.18-rc7?

[Francois Thirioux (fthx)]

Ok, sure I forgot last night to do that.

So, with 3.18rc7 and Utopic's default firmware (25.222.9.0) there IS a speed issue. It seems to me that the dowload speed is as bad as Utopic with 3.16 kernel.

But unfortunately, the latest firmware (-10) cannot be loaded by 3.16 kernel...

[Francois Thirioux (fthx)]

From :

https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1319630/comments/12

I tried to add :

options 11n_disable=8

in

/etc/modprobe.d/iwlwifi.conf

and it seems to allow full speed. I'll confirm this tweak with more testing (ping, speed...) as soon as possible.

[Francois Thirioux (fthx)]

The above tweak does not allow to recover full speed. Sorry, some tests proved one more time that the only satisfatory workaround I found is to disable power management.

[Francois Thirioux (fthx)]

I tried with :

iwlwifi-7260-ucode-22.24.8.0

and current Utopic's 3.16 kernel and I get full speed (with PM on, of course).
So, the current 25.222.9.0 firmware must be faulty.

[penalvch (penalvch)]

Francois Thirioux, could you please provide a URL for the iwlwifi-7260-ucode-22.24.8.0 firmware you tested?

[Francois Thirioux (fthx)]

I tested the -8 firmware which was in linux-firmware.

But anyway :
http://wireless.kernel.org/en/users/Drivers/iwlwifi?action=AttachFile&do=get&target=iwlwifi-7260-ucode-22.24.8.0.tgz

[penalvch (penalvch)]

Francois Thirioux, just to clarify this bug report, this is a regression in Trusty update going from linux-firmware 1.127 to 1.127.10. As per https://launchpad.net/ubuntu/+archive/primary/+files/linux-firmware_1.127.tar.gz this is how 1.127 only included:
/linux-firmware/iwlwifi-7260-7.ucode
/linux-firmware/iwlwifi-7260-8.ucode

However, as per https://launchpad.net/ubuntu/+archive/primary/+files/linux-firmware_1.127.10.tar.gz it includes:
/linux-firmware/iwlwifi-7260-8.ucode
/linux-firmware/iwlwifi-7260-9.ucode

While it is noted that the latest intel upstream firmware (iwlwifi-7260-ucode-23.10.10.0) fixes the issue, either this would have to be backported, the -9 firmware would have to be reverted back to -8, or some special sauce would have to be put in place for your specific variant (i.e. rev and Subsystem) of:
03:00.0 Network controller [0280]: Intel Corporation Wireless 7260 [8086:08b2] (rev 83)
 Subsystem: Intel Corporation Dual Band Wireless-AC 7260 [8086:c270]

I'll update the Bug Description and Tags accordingly.

[Francois Thirioux (fthx)]

Oops.

In my comment :
https://bugs.launchpad.net/ubuntu/+source/linux-firmware/+bug/1289961/comments/48
i say that I'm now using Utopic.

For sure I should have opened a new bug ? (Very sorry if it's the case.)

The Utopic's current linux-firmware 1.138 includes -7, -8 and -9 versions of iwlwifi's firmware.

[penalvch (penalvch)]

Francois Thirioux, no worries. The fact you previously commented you were using Utopic was taken into consideration when I made my comment/updates.

Hence, you wouldn't need to create an additional bug report about this problem unless specifically asked by a developer/triager.

[Francois Thirioux (fthx)]

Bug happens too with old v9 firmware :
23.214.9.0
from Debian Sid :
https://packages.debian.org/sid/firmware-iwlwifi

[Francois Thirioux (fthx)]

OK, I got it.

It seems to me that the -8 version has uAPSD disabled. I don't know how to check that.
In
/sys/module/iwlwifi/parameters
the uapsd_disable is set to N
but as far I can remember uAPSD was disabled when using -8 version because -8 driver was buggy. Is it a kernel stuff to disable it ?

When I use the -9 (e.g. latest 25.228.9.0) version, the download speed is very poor.
Ok, I tried to pass
uapsd_disable=Y
in
/etc/modprobe.d/iwlwifi.conf
but it does not change the loaded parameter
/sys/module/iwlwifi/parameters/uapsd_disable
which is still set to N ,
so I think this parameter is forced by Ubuntu's kernel (that's really out of my knowledge abilities...).

SO the workaround which can lead to a fix for this bug, waiting for 15.04 :
- run Ubuntu 14.10 with -9 firmware (the default one) ;
- remove iwlwifi/iwlmvm modules ;
- reload (via modprobe) iwlwifi module with uapsd_disable=Y option ;
- the download speed is max !

I read that uAPSD was enabled in -9 firmware because bugs have been busted. Maybe some of them survived ?

[Francois Thirioux (fthx)]

Please note that I had to do the same uAPSD disabling in Windows 8/8.1 with latest drivers via the W8's driver parameters window.
Reference (e.g.) :
https://communities.intel.com/message/265839#265839
from
https://communities.intel.com/thread/47983

[Alex Botev (botevmg)]

I can confirm the problem, and also tried to update the kernel to 3.17.3 and use the latest driver 23.11.10.0, but the speed was still much lower than using the 22.24.8.0 so I reverted back. Hope it is resolved.

[Francois Thirioux (fthx)]

FYI there is *no* more issues with current Vivid (kernel 3.19, firmwares 23.(11-13-15).10.0).

[penalvch (penalvch)]

Francois Thirioux, would you need a backport to a release prior to Vivid, or may this be closed as Status Invalid?

[Francois Thirioux (fthx)]

I do not know if the issue still exists in Trusty LTS...
If so, it should be useful to backport a solution but I even do not know if it is possible (last firmwares are 3.17+ compatible).

[penalvch (penalvch)]

Francois Thirioux, this bug report is being closed due to your last comment https://bugs.launchpad.net/ubuntu/+source/linux-firmware/+bug/1289961/comments/67 regarding this being fixed with an update. For future reference you can manage the status of your own bugs by clicking on the current status in the yellow line and then choosing a new status in the revealed drop down box. You can learn more about bug statuses at https://wiki.ubuntu.com/Bugs/Status. Thank you again for taking the time to report this bug and helping to make Ubuntu better. Please submit any future bugs you may find.