Bug#672891: wireless brcms_c_wait_for_tx_completion warning

[Jonathan Nieder <jrnieder@gmail.com>]

Hi,

Touko Korpela wrote:

> Here is log from 3.2.18-1 kernel with X125 laptop. WARNING is there.
[...]
> Linux version 3.2.0-2-686-pae (Debian 3.2.18-1) (debian-kernel@lists.debian.org) (gcc version 4.6.3 (Debian 4.6.3-5) ) #1 SMP Mon May 21 18:24:12 UTC 2012
[...]
> ------------[ cut here ]------------
> WARNING: at [...]/drivers/net/wireless/brcm80211/brcmsmac/main.c:8241 brcms_c_wait_for_tx_completion+0x73/0x7d [brcmsmac]()
> Hardware name: X125                       
> Modules linked in: cryptd aes_i586 aes_generic bridge stp bnep rfcomm powernow_k8 mperf cpufreq_stats cpufreq_userspace cpufreq_conservative cpufreq_powersave fuse loop snd_hda_codec_hdmi joydev arc4 brcmsmac mac80211 brcmutil snd_hda_codec_realtek radeon snd_hda_intel ttm drm_kms_helper drm uvcvideo snd_hda_codec snd_hwdep snd_pcm snd_seq tpm_tis tpm tpm_bios snd_timer ac button videodev media btusb evdev sp5100_tco snd_seq_device video battery processor k10temp snd samsung_laptop i2c_algo_bit pcspkr power_supply i2c_piix4 i2c_core bluetooth cfg80211 shpchp rfkill psmouse serio_raw soundcore crc8 snd_page_alloc cordic ext4 mbcache jbd2 crc16 usb_storage uas sd_mod crc_t10dif ohci_hcd ahci libahci libata ehci_hcd scsi_mod thermal thermal_sys usbcore usb_common sky2 [last unloaded: scsi_wait_scan]
> Pid: 3127, comm: kworker/u:2 Not tainted 3.2.0-2-686-pae #1
> Call Trace:
>  [<c1038468>] ? warn_slowpath_common+0x68/0x79
>  [<f8759e22>] ? brcms_c_wait_for_tx_completion+0x73/0x7d [brcmsmac]
>  [<c1038486>] ? warn_slowpath_null+0xd/0x10
>  [<f8759e22>] ? brcms_c_wait_for_tx_completion+0x73/0x7d [brcmsmac]
>  [<f875110f>] ? brcms_ops_flush+0x1f/0x29 [brcmsmac]
>  [<f86abdca>] ? ieee80211_scan_work+0x36a/0x3fb [mac80211]
>  [<c1049aef>] ? process_one_work+0x112/0x1fa
>  [<f86aba60>] ? ieee80211_scan_rx+0x139/0x139 [mac80211]
>  [<c104a7fa>] ? worker_thread+0xa9/0x122
>  [<c104a751>] ? manage_workers.isra.23+0x13d/0x13d
>  [<c104d13b>] ? kthread+0x63/0x68
>  [<c104d0d8>] ? kthread_worker_fn+0x101/0x101
>  [<c12c5c7e>] ? kernel_thread_helper+0x6/0x10
> ---[ end trace b3b9484c4306740d ]---

This is 20 hours after boot so I'm guessing it's not easy to reproduce.
Alas.  Thanks for reporting it.

Do you think the patch added in 3.2.18 made a difference?  How often
were you getting the wait_for_tx_completion WARNING before, and are
you getting it less often now?  (I'm asking because this information
would probably be helpful to upstream in diagnosing this.)

Hope that helps,
Jonathan