• Michal Kazior's avatar
    mac80211: fix fq lockdep warnings · 59a7c828
    Michal Kazior authored
    Some lockdep assertions were not fulfilled and
    resulted in a kernel warning/call trace if driver
    used intermediate software queues (e.g. ath10k).
    
    Existing code sequences should've guaranteed safety
    but it's always good to be extra careful.
    
    The call trace could look like this:
    
     [ 237.335805] ------------[ cut here ]------------
     [ 237.335852] WARNING: CPU: 3 PID: 1921 at include/net/fq_impl.h:22 fq_flow_dequeue+0xed/0x140 [mac80211]
     [ 237.335855] Modules linked in: ath10k_pci(E-) ath10k_core(E) ath(E) mac80211(E) cfg80211(E)
     [ 237.335913] CPU: 3 PID: 1921 Comm: rmmod Tainted: G        W   E   4.7.0-rc4-wt-ath+ #1377
     [ 237.335916] Hardware name: Hewlett-Packard HP ProBook 6540b/1722, BIOS 68CDD Ver. F.04 01/27/2010
     [ 237.335918]  00200286 00200286 eff85dac c14151e2 f901574e 00000000 eff85de0 c1081075
     [ 237.335928]  c1ab91f0 00000003 00000781 f901574e 00000016 f8fbabad f8fbabad 00000016
     [ 237.335938]  eb24ff60 00000000 ef3886c0 eff85df4 c10810ba 00000009 00000000 00000000
     [ 237.335948] Call Trace:
     [ 237.335953]  [<c14151e2>] dump_stack+0x76/0xb4
     [ 237.335957]  [<c1081075>] __warn+0xe5/0x100
     [ 237.336002]  [<f8fbabad>] ? fq_flow_dequeue+0xed/0x140 [mac80211]
     [ 237.336046]  [<f8fbabad>] ? fq_flow_dequeue+0xed/0x140 [mac80211]
     [ 237.336053]  [<c10810ba>] warn_slowpath_null+0x2a/0x30
     [ 237.336095]  [<f8fbabad>] fq_flow_dequeue+0xed/0x140 [mac80211]
     [ 237.336137]  [<f8fbc67a>] fq_flow_reset.constprop.56+0x2a/0x90 [mac80211]
     [ 237.336180]  [<f8fbc79a>] fq_reset.constprop.59+0x2a/0x50 [mac80211]
     [ 237.336222]  [<f8fc04e8>] ieee80211_txq_teardown_flows+0x38/0x40 [mac80211]
     [ 237.336258]  [<f8f7c1a4>] ieee80211_unregister_hw+0xe4/0x120 [mac80211]
     [ 237.336275]  [<f933f536>] ath10k_mac_unregister+0x16/0x50 [ath10k_core]
     [ 237.336292]  [<f934592d>] ath10k_core_unregister+0x3d/0x90 [ath10k_core]
     [ 237.336301]  [<f85f8836>] ath10k_pci_remove+0x36/0xa0 [ath10k_pci]
     [ 237.336307]  [<c1470388>] pci_device_remove+0x38/0xb0
     ...
    
    Fixes: 5caa328e ("mac80211: implement codel on fair queuing flows")
    Fixes: fa962b92 ("mac80211: implement fair queueing per txq")
    Tested-by: default avatarKalle Valo <kvalo@qca.qualcomm.com>
    Reported-by: default avatarKalle Valo <kvalo@qca.qualcomm.com>
    Signed-off-by: default avatarMichal Kazior <michal.kazior@tieto.com>
    Signed-off-by: default avatarJohannes Berg <johannes@sipsolutions.net>
    59a7c828
tx.c 118 KB