Read busy counters not holding cc_lock spinlock since usb read can't be
performed in interrupt context. Move cc_active and cc_rx counters out of
cc_lock since they are not modified in interrupt context.
Grab cc_lock updating cur_cc_bss_rx in mt76_airtime_report and do not
hold rx_lock in mt76_update_survey.
Moreover grab mt76 mutex in mt76_get_survey before running
mt76_update_survey. This patch fixes the following 'schedule while
atomic'
[ 291.790866] BUG: scheduling while atomic: iw/2161/0x00000202
[ 291.791002] Preemption disabled at:
[ 291.791007] [<0000000000000000>] 0x0
[ 291.791015] CPU: 0 PID: 2161 Comm: iw Tainted: G W 5.4.=
0-rc2-3-ARCH-00104-g9e208aa06c21 #1
[ 291.791017] Hardware name: LENOVO 2349QM6/2349QM6, BIOS G1ETC2WW (2.82=)
08/07/2019
[ 291.791019] Call Trace:
[ 291.791042] dump_stack+0x5c/0x80
[ 291.791049] __schedule_bug.cold+0x8e/0x9b
[ 291.791055] __schedule+0x5f8/0x770
[ 291.791062] schedule+0x43/0xd0
[ 291.791068] schedule_preempt_disabled+0x14/0x20
[ 291.791074] __mutex_lock.isra.0+0x18a/0x530
[ 291.791099] mt76u_rr+0x1f/0x40 [mt76_usb]
[ 291.791113] mt76x02_update_channel+0x22/0x40 [mt76x02_lib]
[ 291.791122] mt76_update_survey+0x42/0xe0 [mt76]
[ 291.791129] mt76_get_survey+0x2f/0x1b0 [mt76]
[ 291.791170] ieee80211_dump_survey+0x5e/0x140 [mac80211]
[ 291.791217] nl80211_dump_survey+0x13c/0x2f0 [cfg80211]
[ 291.791222] ? __kmalloc_reserve.isra.0+0x2d/0x70
[ 291.791225] ? __alloc_skb+0x96/0x1d0
[ 291.791229] netlink_dump+0x17b/0x370
[ 291.791247] __netlink_dump_start+0x16f/0x1e0
[ 291.791253] genl_family_rcv_msg+0x396/0x410
[ 291.791290] ? nl80211_prepare_wdev_dump+0x1b0/0x1b0 [cfg80211]
[ 291.791297] ? _raw_spin_unlock_irqrestore+0x20/0x40
[ 291.791312] ? __wake_up_common_lock+0x8a/0xc0
[ 291.791316] genl_rcv_msg+0x47/0x90
[ 291.791320] ? genl_family_rcv_msg+0x410/0x410
[ 291.791323] netlink_rcv_skb+0x49/0x110
[ 291.791329] genl_rcv+0x24/0x40
[ 291.791333] netlink_unicast+0x171/0x200
[ 291.791340] netlink_sendmsg+0x208/0x3d0
[ 291.791358] sock_sendmsg+0x5e/0x60
[ 291.791361] ___sys_sendmsg+0x2ae/0x330
[ 291.791368] ? filemap_map_pages+0x272/0x390
[ 291.791374] ? _raw_spin_unlock+0x16/0x30
[ 291.791379] ? __handle_mm_fault+0x112f/0x1390
[ 291.791388] __sys_sendmsg+0x59/0xa0
[ 291.791396] do_syscall_64+0x5b/0x1a0
[ 291.791400] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 291.791404] RIP: 0033:0x7f5d0c7f37b7
[ 291.791418] Code: 64 89 02 48 c7 c0 ff ff ff ff eb bb 0f 1f 80 00 00 0=
0 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 2e 00 00 00 0f 05=
<48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 89 54 24 1c 48 89 74 24 10
[ 291.791421] RSP: 002b:00007ffe8b5d0538 EFLAGS: 00000246 ORIG_RAX: 0000=
00000000002e
[ 291.791426] RAX: ffffffffffffffda RBX: 000055a038e6c390 RCX: 00007f5d0=
c7f37b7
[ 291.791430] RDX: 0000000000000000 RSI: 00007ffe8b5d0570 RDI: 000000000=
0000003
[ 291.791434] RBP: 000055a038e718c0 R08: 000055a038e6c02a R09: 000000000=
0000002
[ 291.791438] R10: 000055a03808cb00 R11: 0000000000000246 R12: 000055a03=
8e71780
[ 291.791440] R13: 00007ffe8b5d0570 R14: 000055a038e717d0 R15: 000055a03=
8e718c0
[ 291.791480] NOHZ: local_softirq_pending 202
Fixes: 168aea24f4bb ("mt76: mt76x02u: enable survey support")
Tested-by: Markus Theil <markus.th...@tu-ilmenau.de>
Signed-off-by: Lorenzo Bianconi <lore...@kernel.org>
---
Changes since v1:
- disable BH in mt76_update_survey holding cc_lock
---
drivers/net/wireless/mediatek/mt76/mac80211.c | 29 ++++++++++---------
.../net/wireless/mediatek/mt76/mt76x02_mac.c | 3 ++
2 files changed, 19 insertions(+), 13 deletions(-)
diff --git a/drivers/net/wireless/mediatek/mt76/mac80211.c
b/drivers/net/wireless/mediatek/mt76/mac80211.c
index a962abce98f8..6535921fcea4 100644
--- a/drivers/net/wireless/mediatek/mt76/mac80211.c
+++ b/drivers/net/wireless/mediatek/mt76/mac80211.c
@@ -432,8 +432,6 @@ void mt76_update_survey(struct mt76_dev *dev)
if (!test_bit(MT76_STATE_RUNNING, &dev->state))
return;
- spin_lock_bh(&dev->cc_lock);
-
if (dev->drv->update_survey)
dev->drv->update_survey(dev);
@@ -442,15 +440,11 @@ void mt76_update_survey(struct mt76_dev *dev)
dev->survey_time));
dev->survey_time = cur_time;
- spin_unlock_bh(&dev->cc_lock);
-
if (dev->drv->drv_flags & MT_DRV_SW_RX_AIRTIME) {
- spin_lock_bh(&dev->rx_lock);
- spin_lock(&dev->cc_lock);
+ spin_lock_bh(&dev->cc_lock);
state->cc_bss_rx += dev->cur_cc_bss_rx;
dev->cur_cc_bss_rx = 0;
- spin_unlock(&dev->cc_lock);
- spin_unlock_bh(&dev->rx_lock);
+ spin_unlock_bh(&dev->cc_lock);
}
}
EXPORT_SYMBOL_GPL(mt76_update_survey);
@@ -485,6 +479,7 @@ int mt76_get_survey(struct ieee80211_hw *hw, int idx,
struct mt76_channel_state *state;
int ret = 0;
+ mutex_lock(&dev->mutex);
if (idx == 0 && dev->drv->update_survey)
mt76_update_survey(dev);
@@ -494,8 +489,10 @@ int mt76_get_survey(struct ieee80211_hw *hw, int idx,
sband = &dev->sband_5g;
}
- if (idx >= sband->sband.n_channels)
- return -ENOENT;
+ if (idx >= sband->sband.n_channels) {
+ ret = -ENOENT;
+ goto out;
+ }
chan = &sband->sband.channels[idx];
state = mt76_channel_state(dev, chan);
@@ -511,14 +508,18 @@ int mt76_get_survey(struct ieee80211_hw *hw, int idx,
survey->filled |= SURVEY_INFO_TIME_BSS_RX;
}
- spin_lock_bh(&dev->cc_lock);
- survey->time = div_u64(state->cc_active, 1000);
survey->time_busy = div_u64(state->cc_busy, 1000);
- survey->time_bss_rx = div_u64(state->cc_bss_rx, 1000);
survey->time_rx = div_u64(state->cc_rx, 1000);
+ survey->time = div_u64(state->cc_active, 1000);
+
+ spin_lock_bh(&dev->cc_lock);
+ survey->time_bss_rx = div_u64(state->cc_bss_rx, 1000);
survey->time_tx = div_u64(state->cc_tx, 1000);
spin_unlock_bh(&dev->cc_lock);
+out:
+ mutex_unlock(&dev->mutex);
+
return ret;
}
EXPORT_SYMBOL_GPL(mt76_get_survey);
@@ -622,7 +623,9 @@ mt76_airtime_report(struct mt76_dev *dev, struct
mt76_rx_status *status,
u32 airtime;
airtime = mt76_calc_rx_airtime(dev, status, len);
+ spin_lock(&dev->cc_lock);
dev->cur_cc_bss_rx += airtime;
+ spin_unlock(&dev->cc_lock);
if (!wcid || !wcid->sta)
return;
diff --git a/drivers/net/wireless/mediatek/mt76/mt76x02_mac.c
b/drivers/net/wireless/mediatek/mt76/mt76x02_mac.c
index 41f7c01045b8..2c0bd9aa1987 100644
--- a/drivers/net/wireless/mediatek/mt76/mt76x02_mac.c
+++ b/drivers/net/wireless/mediatek/mt76/mt76x02_mac.c
@@ -1024,8 +1024,11 @@ void mt76x02_update_channel(struct mt76_dev *mdev)
state = mdev->chan_state;
state->cc_busy += mt76_rr(dev, MT_CH_BUSY);
+
+ spin_lock_bh(&dev->mt76.cc_lock);
state->cc_tx += dev->tx_airtime;
dev->tx_airtime = 0;
+ spin_unlock_bh(&dev->mt76.cc_lock);
}
EXPORT_SYMBOL_GPL(mt76x02_update_channel);
--
2.21.0
