Arch Linux

johni

Member

Registered: 2012-02-03

Posts: 102

[SOLVED] linux-3.6.2 breaks wifi for Intel Centrino Advanced-N 6250

After the kernel 3.6.2 update, my wifi no longer works in the iwlwifi driver. Reverting to the 3.5.6 kernel fixes it.

The driver loads, but the wlan0 interface never gets created. 

There is a big difference in the dmesg for iwlwifi between the two kernels:

From the working 3.5.6 kernel:

[    0.932135] iwlwifi: Intel(R) Wireless WiFi Link AGN driver for Linux, in-tree:
[    0.932137] iwlwifi: Copyright(c) 2003-2012 Intel Corporation
[    0.932223] iwlwifi 0000:0d:00.0: >pci_resource_len = 0x00002000
[    0.932226] iwlwifi 0000:0d:00.0: >pci_resource_base = ffffc90012650000
[    0.932229] iwlwifi 0000:0d:00.0: >HW Revision ID = 0x5E
[    0.932317] iwlwifi 0000:0d:00.0: >irq 49 for MSI/MSI-X
[    0.953739] iwlwifi 0000:0d:00.0: >loaded firmware version 41.28.5.1 build 33926
[    0.953890] iwlwifi 0000:0d:00.0: >CONFIG_IWLWIFI_DEBUG disabled
[    0.953892] iwlwifi 0000:0d:00.0: >CONFIG_IWLWIFI_DEBUGFS disabled
[    0.953894] iwlwifi 0000:0d:00.0: >CONFIG_IWLWIFI_DEVICE_TRACING enabled
[    0.953895] iwlwifi 0000:0d:00.0: >CONFIG_IWLWIFI_DEVICE_TESTMODE enabled
[    0.953897] iwlwifi 0000:0d:00.0: >CONFIG_IWLWIFI_P2P disabled
[    0.953899] iwlwifi 0000:0d:00.0: >Detected Intel(R) Centrino(R) Advanced-N + WiMAX 6250 AGN, REV=0x84
[    0.953951] iwlwifi 0000:0d:00.0: >L1 Enabled; Disabling L0S
[    0.954113] iwlwifi 0000:0d:00.0: >RF_KILL bit toggled to enable radio.
[    0.963255] iwlwifi 0000:0d:00.0: >device EEPROM VER=0x540, CALIB=0x6
[    0.963257] iwlwifi 0000:0d:00.0: >Device SKU: 0x1F0
[    0.963259] iwlwifi 0000:0d:00.0: >Valid Tx ant: 0x3, Valid Rx ant: 0x3
[    0.963275] iwlwifi 0000:0d:00.0: >Tunable channels: 13 802.11bg, 24 802.11a channels
[   38.858632] iwlwifi 0000:0d:00.0: >L1 Enabled; Disabling L0S
[   38.858820] iwlwifi 0000:0d:00.0: >Radio type=0x1-0x2-0x0
[   39.103616] iwlwifi 0000:0d:00.0: >L1 Enabled; Disabling L0S
[   39.103814] iwlwifi 0000:0d:00.0: >Radio type=0x1-0x2-0x0

From the broken 3.6.2 kernel:

[    0.906728] Intel(R) Wireless WiFi driver for Linux, in-tree:
[    0.906730] Copyright(c) 2003-2012 Intel Corporation
[    0.906872] iwlwifi 0000:0d:00.0: pci_resource_len = 0x00002000
[    0.906875] iwlwifi 0000:0d:00.0: pci_resource_base = ffffc90001850000
[    0.906877] iwlwifi 0000:0d:00.0: HW Revision ID = 0x5E
[    0.907468] iwlwifi 0000:0d:00.0: irq 41 for MSI/MSI-X
[    0.930835] iwlwifi 0000:0d:00.0: loaded firmware version 41.28.5.1 build 33926

After the firmware loads on 3.6.2, nothing further is logged for my wireless.

The output of lspci:

00:00.0 Host bridge: Intel Corporation 2nd Generation Core Processor Family DRAM Controller (rev 09)
00:01.0 PCI bridge: Intel Corporation Xeon E3-1200/2nd Generation Core Processor Family PCI Express Root Port (rev 09)
00:16.0 Communication controller: Intel Corporation 6 Series/C200 Series Chipset Family MEI Controller #1 (rev 04)
00:1a.0 USB controller: Intel Corporation 6 Series/C200 Series Chipset Family USB Enhanced Host Controller #2 (rev 05)
00:1b.0 Audio device: Intel Corporation 6 Series/C200 Series Chipset Family High Definition Audio Controller (rev 05)
00:1c.0 PCI bridge: Intel Corporation 6 Series/C200 Series Chipset Family PCI Express Root Port 1 (rev b5)
00:1c.2 PCI bridge: Intel Corporation 6 Series/C200 Series Chipset Family PCI Express Root Port 3 (rev b5)
00:1c.3 PCI bridge: Intel Corporation 6 Series/C200 Series Chipset Family PCI Express Root Port 4 (rev b5)
00:1c.5 PCI bridge: Intel Corporation 6 Series/C200 Series Chipset Family PCI Express Root Port 6 (rev b5)
00:1d.0 USB controller: Intel Corporation 6 Series/C200 Series Chipset Family USB Enhanced Host Controller #1 (rev 05)
00:1f.0 ISA bridge: Intel Corporation HM67 Express Chipset Family LPC Controller (rev 05)
00:1f.2 SATA controller: Intel Corporation 6 Series/C200 Series Chipset Family 6 port SATA AHCI Controller (rev 05)
00:1f.3 SMBus: Intel Corporation 6 Series/C200 Series Chipset Family SMBus Controller (rev 05)
01:00.0 VGA compatible controller: NVIDIA Corporation Device 1251 (rev a1)
01:00.1 Audio device: NVIDIA Corporation GF116 High Definition Audio Controller (rev a1)
07:00.0 Ethernet controller: Atheros Communications Inc. AR8151 v2.0 Gigabit Ethernet (rev c0)
0d:00.0 Network controller: Intel Corporation Centrino Advanced-N + WiMAX 6250 [Kilmer Peak] (rev 5e)
13:00.0 Unassigned class [ff00]: Realtek Semiconductor Co., Ltd. RTS5209 PCI Express Card Reader (rev 01)
13:00.1 SD Host controller: Realtek Semiconductor Co., Ltd. RTS5209 PCI Express Card Reader (rev 01)
19:00.0 USB controller: NEC Corporation uPD720200 USB 3.0 Host Controller (rev 04)

Anyone else with this card having troubles?

Last edited by johni (2012-10-18 17:44:19)

flexo3001

Member

From: berlin

Registered: 2012-01-13

Posts: 95

Re: [SOLVED] linux-3.6.2 breaks wifi for Intel Centrino Advanced-N 6250

hey!

i got the same with Intel Pro/Wireless 5100 AGN. can't find something helpful in the internet. the only thing i recognized is that there are changes in the loaded modules. upload tommorow my lsmod with the differences.

peace out,
flexo

---

Fight war not wars, destroy power not people!

brnz

Member

Registered: 2012-09-25

Posts: 8

Re: [SOLVED] linux-3.6.2 breaks wifi for Intel Centrino Advanced-N 6250

I have the same problem, on a ThinkPad X201. I'll try reverting the kernel, be back with updates.

WonderWoofy

Member

From: Los Gatos, CA

Registered: 2012-05-19

Posts: 8,414

Re: [SOLVED] linux-3.6.2 breaks wifi for Intel Centrino Advanced-N 6250

No problems here with intel centrino 6235

johni

Member

Registered: 2012-02-03

Posts: 102

Re: [SOLVED] linux-3.6.2 breaks wifi for Intel Centrino Advanced-N 6250

I started doing a git bisect between 3.5.6 and 3.6.2, but got a git revision at one step that wouldn't compile.   I didn't know about the "git bisect skip", so I just guessed and did a "git bisect bad".  I am going to start over and use the skip option for uncompilable revisions. 

Takes forever to compile/boot/test cycle during a bisect...

If I can find the commit that broke it, I will report it on the kernel bugzilla.

Last edited by johni (2012-10-17 01:25:40)

johni

Member

Registered: 2012-02-03

Posts: 102

Re: [SOLVED] linux-3.6.2 breaks wifi for Intel Centrino Advanced-N 6250

I found the problem!!!

It took hours of "git bisect", reboot, over and over, but I found the commit that broke it:

# bad: [cc5f7e39761382d3a44be70bb665c2c78ae15dac] iwlwifi: implement dynamic opmode loading

Viewing the patch for this revision revealed that it added a module as part of the iwlwifi driver called "iwldvm".
So, I booted the 3.6.2 kernel, and did a "modprobe iwldvm", and up comes my wlan0 interface!

I think is is still a kernel bug that this modules is not automatically loaded, but an easy workaround is just create module load file for it:

/etc/modules-load.d/intel_wifi.conf

# Load extra module needed for iwlwifi in kernel >= 3.6
uwldvm

After doing the modprobe, I ran "mkinitcpio -p linux" just in case it needs to be in the initcpio.

Now the wifi comes up on boot by itself like it should!

WonderWoofy

Member

From: Los Gatos, CA

Registered: 2012-05-19

Posts: 8,414

Re: [SOLVED] linux-3.6.2 breaks wifi for Intel Centrino Advanced-N 6250

Did you then file a bug report?

Also, it probably does not need to be in the initramfs if your computer was booting successfully without it there before.  Remember, the initramfs simply loads what is necessary to hand over the system to the real root.  Though, regenerating certainly won't do any harm, and it certainly doesn't take very long.