brcmsmac wireless driver does not have power management enabled and is eating batteries
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
linux (Ubuntu) |
Expired
|
Undecided
|
Unassigned |
Bug Description
A lot of people have been reporting that the oneiric kernels have been sucking up power (which they were, early on), but a closer look shows that the kernel regressions are mainly all fixed - however, the brcmsmac wireless driver appears to be a main culprit left, sucking up to ~3W of power.
As far as I can tell, the use of the brcmsmac wireless driver co-incided with the use of the introduction of the kernel bug that was making battery life poor for many oneiric users, and I suspect that this is one of the major contributors to that problem. Perhaps the brcmsmac should be rolled back until power management is available, or a push on this driver could possibly enable this feature. Either one would be a good way to extend battery life for laptop users.
I am using: Ubuntu 3.0.0-12.19-generic 3.0.4 (Oneiric, with up to date packages)
The important line from lspci is:
03:00.0 Network controller [0280]: Broadcom Corporation BCM43224 802.11a/b/g/n [14e4:4353] (rev 01)
Subsystem: Apple Computer Inc. Device [106b:0093]
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: 256 bytes
Interrupt: pin A routed to IRQ 17
Region 0: Memory at c1b00000 (64-bit, non-prefetchable) [size=16K]
Kernel driver in use: brcmsmac
Kernel modules: wl, bcma, brcmsmac
From powertop:
The battery reports a discharge rate of 16.6 W
Summary: 0.0 wakeups/second, 0.0 GPU ops/second and 0.0 VFS ops/sec
Power est. Usage Events/s Category Description
2.61 W 100.0% Device Radio device: brcmsmac
2.35 W 60.0% Device Display backlight
759 mW 29.5 ms/s 0.0 Process /usr/sbin/
727 mW 20.5% Device Audio codec alsa:hwC0D0: mbp55 (Cirrus Logic)
564 mW 40.7 pkts/s Device Network interface: wlan0 (brcmsmac)
469 mW 18.3 ms/s 0.0 Process /usr/bin/knotify4
279 mW 10.9 ms/s 0.0 Process /usr/lib/
260 mW 10.1 ms/s 0.0 Process powertop
and, of course some output from iwconfig:
wlan0 IEEE 802.11abgn ESSID:"XXXXXXXXXX"
Bit Rate=54 Mb/s Tx-Power=19 dBm
Retry long limit:7 RTS thr:off Fragment thr:off
Power Management:off
Link Quality=47/70 Signal level=-63 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:15 Invalid misc:2221 Missed beacon:0
And finally:
"sudo iwconfig wlan0 power on" gives:
Error for wireless request "Set Power Management" (8B2C) :
SET failed on device wlan0 ; Operation not supported.
What I expected:
Ubuntu would not use a wireless driver on laptops that eats 3W of power and can't be set to use less power.
What happened:
My batteries are being drained by a wireless card that is constantly hot (I can feel it through the case) for which no option to enable power management exists.
Changed in linux (Ubuntu): | |
status: | Incomplete → Confirmed |
This bug is missing log files that will aid in diagnosing the problem. From a terminal window please run:
apport-collect 867869
and then change the status of the bug to 'Confirmed'.
If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.
This change has been made by an automated script, maintained by the Ubuntu Kernel Team.