Difference between revisions of "Broadcom wireless"

Revision as of 20:18, 5 March 2013

zh-CN:Broadcom wireless

Introduction

Broadcom has been notorious in its support for its Wi-Fi cards on GNU/Linux. Until recently, most Broadcom chips were either entirely unsupported or required the user to tinker with firmware. A limited set of wireless chips were supported by various reverse-engineered drivers (brcm4xxx, b43, etc.). The reverse-engineered b43 drivers have been in the kernel since 2.6.24.

In August 2008, Broadcom released the 802.11 Linux STA driver officially supporting Broadcom wireless hardware on GNU/Linux. These are restrictively licensed drivers, but Broadcom promised to work towards a more open approach in the future. Further, they do not work with hidden ESSIDs.

In September 2010, Broadcom finally released fully open source drivers for its hardware. This driver, brcm80211, has been included into the kernel since 2.6.37. With the release of 2.6.39, these drivers have been renamed to brcmsmac and brcmfmac.

At the time of writing, there are three choices for users with Broadcom Wi-Fi chipsets:

Determine which driver you need/can use

First, determine your card's PCI-ID. Type the following (case-sensitive) command into a console:

$ lspci -vnn | grep 14e4:

Then check your card against this list of supported b43 devices and this list of supported brcm80211 devices.

Getting the driver

brcmsmac/brcmfmac

The brcm80211 drivers are included in the kernel. They are named brcmsmac for PCI cards and brcmfmac for SDIO devices.

These drivers should be automatically loaded during start-up and no further action should be required of the user. If the driver does not automatically load, try the following commands:

# modprobe brcmsmac

or

# modprobe brcmfmac

b43/b43legacy

The drivers are included in the kernel since 2.6.24.

Loading the b43/b43legacy kernel module

Verify which module you need by looking up your device here. You can also check by computer model here. Blacklist the other module (either b43 or b43legacy) to prevent possible problems/confusion. For instructions, see Kernel_modules#Blacklisting.

Install the appropriate b43-firmware^AUR or b43-firmware-legacy^AUR package from the AUR.

You can now configure your device.

broadcom-wl

For users of the broadcom-wl driver, there is a PKGBUILD available in the AUR named broadcom-wl^AUR.

Loading the wl kernel module

The wl module may need to be manually loaded if there are other usable modules present. Before loading the wl module, remove the b43 or other module that may have been automatically loaded instead:

# rmmod b43

Also unload ssb, if loaded:

# rmmod ssb

Load the wl module

# modprobe wl

The wl module should automatically load lib80211 or lib80211_crypt_tkip. Check with lsmod to see if this is the case. If not, you may need to add one of those two modules as well.

# modprobe lib80211

or

# modprobe lib80211_crypt_tkip

If you installed the driver directly from Broadcom, you may also need to update the dependencies:

# depmod -a

To make the module load at boot, refer to Kernel modules.

You can also blacklist other modules (to prevent them from interfering) in /etc/modprobe.d/modprobe.conf. To blacklist a module, refer to Kernel modules#Blacklisting.

Troubleshooting

Wi-Fi card does not work or show up after kernel upgrade (brcmsmac)

This is caused by the kernel using the bcma module instead of the brcmsmac module. The solution is to blacklist the bcma module. For instructions, see Kernel_modules#Blacklisting.

Wi-Fi card does not work/show up (broadcom-wl)

Check if you are loading the correct modules. You may need to blacklist the brcm80211, b43, and ssb kernel modules to prevent them from loading automatically. For instructions, see Kernel_modules#Blacklisting.

Check if you updated your module dependencies:

# depmod -a

• Verify that your wireless interface(s) appear using ip addr.
• You may need to restart your machine to see the device appear in iwconfig or ip addr.
• If you have recently upgraded your kernel, you need to rebuild the broadcom-wl package with the new kernel installed to update the module.

Interfaces swapped (broadcom-wl)

Users of the broadcom-wl driver may find their Ethernet and Wi-Fi interfaces have been swapped. The udev page explains how to resolve this. Create a file named /etc/udev/rules.d/10-network.rules and bind the MAC address of each of your cards to a certain interface name:

SUBSYSTEM=="net", ATTR{address}=="aa:bb:cc:dd:ee:ff", NAME="eth0"
SUBSYSTEM=="net", ATTR{address}=="ff:ee:dd:cc:bb:aa", NAME="eth1"

Ensure that the interface name appears correctly in the configuration files that refer to it.

Suppressing console messages

You may continuously get some verbose and annoying messages during the boot, similar to

phy0: brcms_ops_bss_info_changed: arp filtering: enabled true, count 0 (implement)
phy0: brcms_ops_bss_info_changed: qos enabled: false (implement)
phy0: brcms_ops_bss_info_changed: arp filtering: enabled true, count 1 (implement)
enabled, active

These do not seem to be suppressible via normal means, such as setting MaxLevelConsole in /etc/systemd/journald.conf. To hide them, you must lower the level at which dmesg messages are printed to the console. This can be done on start-up by creating a simple systemd service.

Create a file in /etc/systemd/system/ called brcms_suppression.service or something similar:

brcms_suppression.service

[Unit]
Description=Broadcom console message suppression script

[Service]
Type=oneshot
RemainAfterExit=yes
ExecStart=/bin/dmesg -n 3

[Install]
WantedBy=multi-user.target

Like all other systemd services, you can then enable it with

# systemctl enable brcms_suppression

Miscellaneous user notes

• In my Dell Inspiron Laptop, I have a Broadcom BCM4401 Ethernet card and a Broadcom BCM4328 wireless card. If I just remove b43, I can load the wl driver, but no wireless card shows up. However, if I first remove the b44 (and ssb) driver for my Ethernet card, and then load the wl driver, I get a wireless device using the name eth0. Afterwards, I can load b44 again, to have an Ethernet eth1 device.

• I could not get the BCM4313 chip on a Lenovo B560 to work before following these steps:
  1. "Load defaults" in the BIOS. After that, the wireless was working under MS Windows. There are not many options in there, so I do not know what the reset may have changed, but it did the trick.
  2. Blacklist the acer_wmi module. For testing, you can add the following to the kernel line in GRUB: acer_wmi.disable=1

• I have found that to get the wl drivers working for the Broadcom 4313 chip, you need to blacklist brcm80211 along with b43 and ssb.

--Admiralspark, 20 June 2011

• If you notice slow wireless speeds when your laptop/netbook is not connected to AC power, you may need to disable Wi-Fi power management by adding the following line (assuming wlan0 is your wireless device) iwconfig wlan0 power off to /etc/rc.local and create an empty file /etc/pm/power.d/wireless. In case you also experience interface swapping (discussed above), you might want to add another line for the second interface name as well. The command will have no effect on the wired interface.

--Tom.yan, 16 August 2011

• In my case on a HP pavilion netbook DM1 with a BCM4313 chip, with the original kernel brcmsmac driver, the LED didn't work, the power was awful, and it kept loosing the signal all the time, unless very close to the Wi-Fi hotspot. The last Broadcom driver wl solved everything. So in some cases, it's actually better than the kernel driver. However, I had to install it in the initramfs image, along with lib80211 and lib80211_crypt_tkip to avoid a recurring kernel panic.

--Ivanoff, 18 March 2012

• On a similar HP DM1 netbook I found the brcmsmac driver did not work either. The kernel panic can also be solved by blacklisting the brcmsmac, b43 and wl drivers. In rc.local you can modprobe wl without problems. On a sidenote: I get hard lockups, without any way to debug because there is nothing in kernel.log. Not sure if related to the wl driver though.

--Wilco, 5 May 2012

• Likewise, my HP Pavilion g7-1374ca also had problems with stock kernel drivers. I downloaded Broadcom tarball, but it wouldn't compile in 3.4.3. I removed the #include <asm/system.h> line and commented out a line referencing .ndo_set_multicast_list (there's only one). Then I was able to compile and load the module for a 100% strength signal, no lockups so far.

• On a Dell Inspiron N5110 with BCM4313, when the wireless was hardware-off, the system would always hang at boot with the kernel brcmsmac driver. Using the broadcom-wl driver the problem was solved.

--Nplatis, 14 October 2012

• On a Dell M4700 with BCM4313 got hideously slow "performance" with default driver -- switched to broadcom-wl and got near advertised link rate speed (65 to 72 Mb/sec)...until restarting, then was not able to associate with wireless access point. The solution was to blacklist the kernel modules dell_wmi and cfg80211.

--virtualeyes, 23 February 2013