8086:08b1 [Toshiba Satellite P55-A5312] Intel 7260 Wifi regularly crashes

JamesE, thank you for reporting this bug and helping make Ubuntu better. Could you please test the latest upstream kernel available (v3.13-rc3 as rc4 is missing the necessary files) following https://wiki.ubuntu.com/KernelMainlineBuilds ? It will allow additional upstream developers to examine the issue. Once you've tested the upstream kernel, please comment on which kernel version specifically you tested. If this bug is fixed in the mainline kernel, please add the following tags:
kernel-fixed-upstream
kernel-fixed-upstream-VERSION-NUMBER

where VERSION-NUMBER is the version number of the kernel you tested. For example:
kernel-fixed-upstream-v3.13-rc4

This can be done by clicking on the yellow circle with a black pencil icon next to the word Tags located at the bottom of the bug description. As well, please remove the tag:
needs-upstream-testing

If the mainline kernel does not fix this bug, please add the following tags:
kernel-bug-exists-upstream
kernel-bug-exists-upstream-VERSION-NUMBER

As well, please remove the tag:
needs-upstream-testing

Once testing of the upstream kernel is complete, please mark this bug's Status as Confirmed. Please let us know your results. Thank you for your understanding.

Thank you , Christopher.

As I noted in the bug report, I did install the mainline kernel 3.13 yesterday, and although the firmware crash still occurs, it appears there is restart logic in iwlwifi to restart the connection automatically. Beforehand, I would have to use rmmod and modprobe to reload iwlwifi manually.

In fact, I noted this restart happening just before I reported the issue.

My gut feeling (not very technical!) is that the root cause is probably in the 7260 firmware code. Please note that I am using the latest version -- version 7 -- for the 7260. If there is a later version, please let me know!

Thanks!

Sorry, I should be more precise. It WAS RC3 (ie. the latest) of Kernel 3.13, because although I can find headers for RC4, there is no image for it.

I downloaded the firmware driver from here:

http://wireless.kernel.org/en/users/Drivers/iwlwifi

The tar file has the name iwlwifi-7260-ucode-22.1.7.0.tgz.

JamesE, thank you for providing the requested information. Could you please confirm this issue exists with the latest development release of Ubuntu (without changing the default firmware)? ISO images are available from http://cdimage.ubuntu.com/daily-live/current/ . If the issue remains, could you please just make a comment to this?

I downloaded and tried (via the ISO image) Ubuntu 13.10, for about a few hours, and the wifi connection held up fine without any disconnects.

Maybe 13.10 really does fix the issue -- or maybe I just need to try testing it more?

But 13.10 uses kernel 3.12, whereas I have installed kernel 3.13 on my hard drive where I am experiencing the disconnects. It's unlikely kernel 3.13's regressed -- so maybe the problem really is in the 7260 firmware??

What's weird is that I diff'd a copy of 13.10's 7260 firmware against what the firmware I'm using on kernel 3.13 (that disconnects), and both appear to be identical. So, if the kernel's not regressed and the 7260 firmware is the same, I cannot explain why wifi connection appears to be stable under 13.10, but not under 12.04 with kernel 3.13...

To make matters more complicated, I've just gone back to http://wireless.kernel.org, and now find someone's put up a new version of the 7260 release 7 firmware! The full 7260 firmware version is 22.1.7.0 whereas I'm sure it was 22.0.7.0 a couple days' ago...

I've just replaced my previous 7260 firmware with the new version (22.1.7.0) from the kernel.org website. It appears to work OK so far.

I'll let you know how I get on with it.

Christopher, thank you for your reply and help here!

My plan is to upgrade to the official 13.10 release, and check over a longer period of time whether I still get any wifi disconnects. If I find a problem, I will raise a new issue and notify you of it.

Note I will keep with the 7260 firmware as installed by 13.10 -- at least for now.

Please note there has been reported a recent spate of instability issues using the Intel 7260 board with Ubuntu, and at least in my case, my problem was fixed (or at very least, greatly reduced) by moving from 12.04, which does NOT support the 7260, to 13.10 which DOES support it. It may be worth recommending this course of action to others.

Thanks!!

Hi, unfortunately after installing an official release of 13.10 the wifi crashing issue has just occurred! Here's the trace from dmesg:

[ 398.297590] iwlwifi 0000:02:00.0: Firmware error during reconfiguration - reprobe!
[ 398.297594] iwlwifi 0000:02:00.0: FW error in SYNC CMD MAC_CONTEXT_CMD
[ 398.297598] CPU: 1 PID: 2211 Comm: kworker/1:2 Not tainted 3.12.0-7-generic #15-Ubuntu
[ 398.297599] Hardware name: TOSHIBA Satellite P55-A/VG10ST, BIOS 1.40 10/09/2013
[ 398.297615] Workqueue: events ieee80211_restart_work [mac80211]
[ 398.297618] 00000000000001f4 ffff880194307b40 ffffffff81711aee ffff88019474c000
[ 398.297622] ffff880194307ba8 ffffffffa01df3cf 0000000000000000 0000000000000000
[ 398.297625] ffff8801925edec0 ffffffff81088eb0 ffff880194307b70 ffff880194307b70
[ 398.297628] Call Trace:
[ 398.297635] [<ffffffff81711aee>] dump_stack+0x45/0x56
[ 398.297648] [<ffffffffa01df3cf>] iwl_trans_pcie_send_hcmd+0x53f/0x5d0 [iwlwifi]
[ 398.297652] [<ffffffff81088eb0>] ? wake_up_atomic_t+0x30/0x30
[ 398.297659] [<ffffffffa05012dd>] iwl_mvm_send_cmd+0x2d/0x90 [iwlmvm]
[ 398.297665] [<ffffffffa0501381>] iwl_mvm_send_cmd_pdu+0x41/0x50 [iwlmvm]
[ 398.297670] [<ffffffffa04ff848>] iwl_mvm_mac_ctxt_send_cmd+0x28/0x60 [iwlmvm]
[ 398.297674] [<ffffffffa0500618>] iwl_mvm_mac_ctxt_cmd_station+0xd8/0x140 [iwlmvm]
[ 398.297679] [<ffffffffa05007f3>] iwl_mvm_mac_ctx_send+0x53/0x90 [iwlmvm]
[ 398.297684] [<ffffffffa0500f80>] iwl_mvm_mac_ctxt_add+0x20/0x90 [iwlmvm]
[ 398.297689] [<ffffffffa04fd195>] iwl_mvm_mac_add_interface+0xa5/0x2c0 [iwlmvm]
[ 398.297693] [<ffffffff815dc9e7>] ? led_trigger_event+0x47/0x60
[ 398.297708] [<ffffffffa048f7a7>] ieee80211_reconfig+0x587/0x1400 [mac80211]
[ 398.297716] [<ffffffffa04641f7>] ieee80211_restart_work+0x87/0xa0 [mac80211]
[ 398.297720] [<ffffffff810803d3>] process_one_work+0x183/0x450
[ 398.297723] [<ffffffff81081171>] worker_thread+0x121/0x410
[ 398.297726] [<ffffffff81081050>] ? rescuer_thread+0x3e0/0x3e0
[ 398.297729] [<ffffffff81088060>] kthread+0xc0/0xd0
[ 398.297732] [<ffffffff81087fa0>] ? kthread_create_on_node+0x120/0x120
[ 398.297736] [<ffffffff817227fc>] ret_from_fork+0x7c/0xb0
[ 398.297739] [<ffffffff81087fa0>] ? kthread_create_on_node+0x120/0x120
[ 398.297742] iwlwifi 0000:02:00.0: Failed to send MAC context (action:1): -5
[ 398.297841] iwlwifi 0000:02:00.0: PHY ctxt cmd error. ret=-5
[ 398.297843] iwlwifi 0000:02:00.0: Failed to add PHY context
[ 398.297844] ------------[ cut here ]------------
[ 398.297856] WARNING: CPU: 1 PID: 2211 at /build/buildd/linux-3.12.0/net/mac80211/util.c:1527 ieee80211_reconfig+0x1143/0x1400 [mac80211]()

Please note: I have NOT changed the kernel, neither have I updated the firmware code for the 7260. This is all from a standard 13.10 install.

What is good is that iwlwifi restarts automatically and I have a working wifi connection.

Should I reopen this issue?

Thank you!

JamesE, thank you for your comments. Let us reopen this, and reassign to linux (Ubuntu) given it's fully reproducible in a default install, as well as the linux-lts-raring (Ubuntu) package.

With this in mind, your call trace notes:
3.12.0-7-generic

Did you mean stock Trusty/14.04?

As well, did this issue not occur in a release prior to Raring/13.04?

I am sorry for the ambiguity. I initially installed an official 13.10 release (totally wiping over my previous 12.04 install). But the first time I checked for updates, it immediately upgraded me to 14.04 -- even though the "System About" box from the gnome desktop still tells me I'm on 13.10!

I assume I am now on Trusty/14.04. Is there any way to 100% verify which release I'm officially on?

As for a pure 13.10 install, I ran a 13.10 release from CD over the weekend for a number of hours, and I did not get any wifi disconnect or crash at all. However, the same could initially be said for my 14.04 install before I got the crash last night. Here, the wifi error just happened once, whereas before the error happened over and over again.

Would you like me to temporarily try a newer version of the 7260 firmware?

JamesE, thank you for the requested information. It is understood that when you test the live environment of both 13.10 and 14.04 it works, but when installed and it crashes.

Given that according to http://wireless.kernel.org/en/users/Drivers/iwlwifi your card is supported on kernel series 3.10.x+, it would be helpful if you tested the compat-wireless/linux-next development branch noted in https://wiki.ubuntu.com/Kernel/LinuxWireless#Compat-wireless_from_upstream . Could you please test this and advise to the results?

I'm not sure I would say it 100% works in the 13.10 live environment. I just noticed that iwlwifi didn't crash while testing for a number of hours. Even when the crash did occur on my installed 14.04, I'd been running it without crashes for a significantly longer period of time than the live 13.10.

I have gone to http://drvbp1.linux-foundation.org/~mcgrof/rel-html/backports/ (for linux-next upstream backports), and downloaded the tar file for backports-3-12.2-1. However, I notice most of it is .c and .h source code. I'd appreciate it if you could tell me how can I install this tar file into my system. Sorry if I seem a bit "thick" at this point!

Thanks!

JamesE, instructions on building may be found at https://backports.wiki.kernel.org/index.php/Documentation .

Same problem with this wireless card (7260 rev 73)
Ubuntu stable 13.10, kernel 3.11.0-14-generic #21-Ubuntu SMP.
after firmware upgrade to 22.1.7.0 it is much better and problems occurs only when:
a) too much AP's around me (office)
b) >5 meter away from AP (signal strength is low, in Win8 works perfectly)
wifi reconnects again every minute or two.

maybe helps futher info about signal strength and frequency
wlan0 IEEE 802.11bgn ESSID:"************"
          Mode:Managed Frequency:2.462 GHz Access Point: 00:90:4C:91:00:01
          Bit Rate=6 Mb/s Tx-Power=0 dBm
          Retry long limit:7 RTS thr:off Fragment thr:off
          Encryption key:off
          Power Management:on
          Link Quality=31/70 Signal level=-79 dBm
          Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
          Tx excessive retries:0 Invalid misc:13 Missed beacon:0

Roman, thank you for your comment. So your hardware may be tracked, could you please file a new report 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://help.ubuntu.com/community/ReportingBugs

penalvch, I apologize for the delay getting back to you.

A couple days' ago, I tried making the wireless backport code for 3.12, but I immediately got several errors in the C compilation. I am sorry, but I can't give you the errors right now as I'm at work, but I remember they were to do with a set of undeclared #define's...? I'm being vague here, and I'll get you a listing of the errors later on.

Because i could not build the backport, I did as Roman has done here and upgraded my 7260 firmware to 22.1.7.0. The stability of my wifi connection is much better now, and I have yet to experience another crash in ieee80211_reconfig as I got before.

If you can help me fix the backport code, I am happy to revert back to the original firmware from 14.04, and then install the backport as you suggested. But I suspect the issue is with the 7260 firmware itself.

Note that I discovered this bug fix made a month ago to the firmware driver to fix an interrupt issue in there:

http://git.kernel.org/cgit/linux/kernel/git/iwlwifi/iwlwifi-fixes.git/commit/?id=6960a059b2c618f32fe549f13287b3d2278c09e9

It may be worth pointing developers at this link, so they are aware of the bug fix.

Thanks again for all your help!!

penalvch, sorry but the command failed at the point of cloning the linux repository. To make it clear what the error is, I've run the git clone command on its own:

jamesmeast:~$ git clone git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-stable.git
Cloning into 'linux-stable'...
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.

--

I'm not a git expert at all -- can you advise me, please? Note I have not done any git setup prior to running this command.

Thanks!

penalvch, sorry but on the make -j.. command I get loads of the following errors referring to what appears to be a corrupt generated arch/x86/include/generated/asm/syscalls_64.h file:

__SYSCALL_COMMON(ESC[35mESC[K/home/jamesmeast/linux-stable/arch/x86/syscalls/syscall_64.tblESC[mESC[KESC[36mESC[K:ESC[mESC[KESC[01;31mESC[K0ESC[mESC[K, sys_read, sys_read)
__SYSCALL_COMMON(ESC[35mESC[K/home/jamesmeast/linux-stable/arch/x86/syscalls/syscall_64.tblESC[mESC[KESC[36mESC[K:ESC[mESC[KESC[01;31mESC[K1ESC[mESC[K, sys_write, sys_write)

It appears to have been generated with esc characters for colorizing the line numbers?? I guess it shouldn't do that.

Do you know what I've done wrong?

penavlch, The new git clone command worked OK last night. However, I think the commit status of the fix I'm checking out has changed, because I now get:

jamesmeast:~/linux$ git checkout 755ca0109f973f23fced94f8dcd8c60e013f270a
fatal: reference is not a tree: 755ca0109f973f23fced94f8dcd8c60e013f270a

Can you tell me what the new checkout command should be, please?

JamesE, thank you for your comments. Try:
sudo apt-get -y install git build-essential kernel-package fakeroot libncurses5-dev && cd $HOME && git clone git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git && cd linux && git checkout 6960a059b2c618f32fe549f13287b3d2278c09e9 && cp /boot/config-`uname -r` .config && yes '' | make oldconfig && make clean && make -j `getconf _NPROCESSORS_ONLN` deb-pkg LOCALVERSION=-custom && cd .. && sudo dpkg -i *.deb

For future reference, you may visually scan git commits you want to build against locally with a GUI via the gitk package:
sudo apt-get -y install gitk

It tends to be a bit faster than using git web interfaces, and more agreeable than using the command line:
git log

penalvch, at last the custom kernel build worked OK! I am now running a custom version:
jamesmeast:~$ uname -a
Linux Rogan-Josh-JME 3.12.0-custom #1 SMP Sun Dec 29 13:28:56 EST 2013 x86_64 x86_64 x86_64 GNU/Linux

However, I was expecting the time/date of the 7260 firmware to change to today's date as well. However, this is what I have instead:

-rw-r--r-- 1 jamesmeast jamesmeast 668K 12/16/2013 03:44:07 AM /lib/firmware/iwlwifi-7260-7.ucode

This is the same date/time as I had for the 7260 firmware I deliberately upgraded to a few days' ago. Would you like me to revert back to the original firmware that came with 14.04?

JamesE, thank you for your comments. As the commit you just built doesn't adjust the firmware at all as noted in http://kernel.ubuntu.com/git?p=ubuntu/ubuntu-trusty.git;a=commitdiff;h=6960a059b2c618f32fe549f13287b3d2278c09e9 the expectation is the firmware would not change, while the potential expectation is that your issue is resolved for the default firmware.

Hence, could you please return the firmware to the defaults from Ubuntu, and advise to the results? This will provide an important data point on your issue.

penalvch, thank you for confirming what the commit was for.

I have now reverted back to the original firmware from Ubuntu. FYI, the firmware is dated 10/21/2013. I will let you know how I get on in due course.

Thank you!

penalch, I've been trying this custom kernel for the past 2 days, and I've yet to notice any wifi disconnects or errors in the log. NOTE: This is with the original 10/21/2013 firmware, too.

I'll monitor wifi stability over the next week or so -- and will report it if I find further issues -- but so far this customized kernel's done its job and been a success!

I'd appreciate it if you could coordinate the commit mentioned previously here into an official kernel release for 14.04.

Thank you!

penalvch, later today internet download speed became significantly reduced -- although connectivity was not lost. I looked in dmesg to see the following trace repeating over and over again:

[28021.389611] ieee80211 phy0: Hardware restart was requested
[28021.389995] iwlwifi 0000:02:00.0: L1 Disabled; Enabling L0S
[28021.390138] iwlwifi 0000:02:00.0: L1 Disabled; Enabling L0S
[28022.399946] iwlwifi 0000:02:00.0: Microcode SW error detected. Restarting 0x2000000.
[28022.399950] iwlwifi 0000:02:00.0: CSR values:
[28022.399951] iwlwifi 0000:02:00.0: (2nd byte of CSR_INT_COALESCING is CSR_INT_PERIODIC_REG)
[28022.399956] iwlwifi 0000:02:00.0: CSR_HW_IF_CONFIG_REG: 0X00489204
[28022.399961] iwlwifi 0000:02:00.0: CSR_INT_COALESCING: 0X8000ff40
[28022.399966] iwlwifi 0000:02:00.0: CSR_INT: 0X00000000
[28022.399971] iwlwifi 0000:02:00.0: CSR_INT_MASK: 0X00000000
[28022.399976] iwlwifi 0000:02:00.0: CSR_FH_INT_STATUS: 0X00000000
[28022.399980] iwlwifi 0000:02:00.0: CSR_GPIO_IN: 0X00000000
[28022.399984] iwlwifi 0000:02:00.0: CSR_RESET: 0X00000000
[28022.399989] iwlwifi 0000:02:00.0: CSR_GP_CNTRL: 0X080403c5
[28022.399994] iwlwifi 0000:02:00.0: CSR_HW_REV: 0X00000144
[28022.399999] iwlwifi 0000:02:00.0: CSR_EEPROM_REG: 0X00000000
[28022.400004] iwlwifi 0000:02:00.0: CSR_EEPROM_GP: 0X80000000
[28022.400009] iwlwifi 0000:02:00.0: CSR_OTP_GP_REG: 0X803a0000
[28022.400013] iwlwifi 0000:02:00.0: CSR_GIO_REG: 0X00080044
[28022.400017] iwlwifi 0000:02:00.0: CSR_GP_UCODE_REG: 0X00000000
[28022.400021] iwlwifi 0000:02:00.0: CSR_GP_DRIVER_REG: 0X00000000
[28022.400026] iwlwifi 0000:02:00.0: CSR_UCODE_DRV_GP1: 0X00000000
[28022.400030] iwlwifi 0000:02:00.0: CSR_UCODE_DRV_GP2: 0X00000000
[28022.400034] iwlwifi 0000:02:00.0: CSR_LED_REG: 0X00000060
[28022.400039] iwlwifi 0000:02:00.0: CSR_DRAM_INT_TBL_REG: 0X880d0cd2
[28022.400045] iwlwifi 0000:02:00.0: CSR_GIO_CHICKEN_BITS: 0X27800200
[28022.400049] iwlwifi 0000:02:00.0: CSR_ANA_PLL_CFG: 0Xd55555d5
[28022.400053] iwlwifi 0000:02:00.0: CSR_HW_REV_WA_REG: 0X0001001a
[28022.400057] iwlwifi 0000:02:00.0: CSR_DBG_HPET_MEM_REG: 0Xffff0010
[28022.400059] iwlwifi 0000:02:00.0: FH register values:
[28022.400073] iwlwifi 0000:02:00.0: FH_RSCSR_CHNL0_STTS_WPTR_REG: 0X0d1fa500
[28022.400088] iwlwifi 0000:02:00.0: FH_RSCSR_CHNL0_RBDCB_BASE_REG: 0X00d0df60
[28022.400101] iwlwifi 0000:02:00.0: FH_RSCSR_CHNL0_WPTR: 0X00000090
[28022.400115] iwlwifi 0000:02:00.0: FH_MEM_RCSR_CHNL0_CONFIG_REG: 0X80801114
[28022.400130] iwlwifi 0000:02:00.0: FH_MEM_RSSR_SHARED_CTRL_REG: 0X000000fc
[28022.400146] iwlwifi 0000:02:00.0: FH_MEM_RSSR_RX_STATUS_REG: 0X07030000
[28022.400159] iwlwifi 0000:02:00.0: FH_MEM_RSSR_RX_ENABLE_ERR_IRQ2DRV: 0X00000000
[28022.400173] iwlwifi 0000:02:00.0: FH_TSSR_TX_STATUS_REG: 0X07ff0001
[28022.400189] iwlwifi 0000:02:00.0: FH_TSSR_TX_ERROR_RE...

penalvch, thank you for your patience. The URL in your last post looks to be for the 3160 card, whereas I have the 7260. So I have instead downloaded the version from http://wireless.kernel.org/en/users/Drivers/iwlwifi?action=AttachFile&do=get&target=iwlwifi-7260-ucode-22.1.7.0.tgz, and upgraded my driver to this version.

I will report back progress in due course.

Please note: despite there not being 100% success with just the fix applied to the kernel, it still appeared to make my wifi connectivity much more stable than previous. Therefore, in my view, it is still a valid fix -- and should be promoted into an official kernel release.

Thanks!

Hi,

For information,
I'm experiencing the same "Microcode SW error detected" problem with Intel 7260 wifi chipset. I've installed the firmware given by JamesE in comment #35 and I confirm the connectivity is much more stable. No more disconnect in 1 hour.

penalvch, I've been running with the iwlwifi patch + the new 22.1.7.0 7260 firmware for the past few days, and I haven't seen a single error written to dmesg, ie. it's been running flawlessly!
Therefore, unless you'd like to test further, please feel free to close this issue!

Following adrien-loxq's success with the new 22.1.7.0 firmware in comment #36 , I would greatly appreciate it if both this 7260 firmware and the iwlwifi patch were pushed into an official Ubuntu release.

Thank you for all your help!!

Before this firmware upgrade, bluetooth was OK. Now, I can't use bluetooth anymore (Intel 7260 chipset provides both Wifi and Bluetooth. On my computer at least). I'm not sure the problem is related, I need to test it furthermore.

I'll post more information on this bug report soon.

Adrien loxq, thank you for your comment. As you are not the original reporter, this report is not covering your hardware or problem. Despite this, so your hardware and problem may be tracked, please feel free to 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

This is a well known issue with Intel WiFi adapters (on both Linux and Windows).

The only reliable "workaround" I've found is to disable 802.11n:

1. Open terminal.
2. sudo vi /etc/modprobe.d/iwlwifi-disable11n.conf
3. Add this line: options iwlwifi 11n_disable=1
4. Save and restart.

I've had this issue on 3 laptops, all with the Intel 7260. Disabling 802.11n made the connection stable on all of them (i.e no more frequent sporadic drop-outs).

Scott Deagan, 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

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 u...

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

This seems to be fixed now. I am running with n mode and power saving with no problems as of 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

JamesE, could you please test the latest Trusty release via http://releases.ubuntu.com/trusty/ and advise to the results?

Joel Schopp, please do not close this report until it is resolved for the original reporter (JamesE).

penalvch, I've now been on 14.04 LTS since it came out, and my wifi is 100% stable. This is without patches or workarounds etc.

Consider this issue closed.

Thank you for all your help!

James.

JamesE, this bug report is being closed due to your last comment https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1262388/comments/46 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.