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| author |   Jiri Kosina <jkosina@suse.cz> | 2021-03-02 11:34:51 +0100 |
|---|---|---|
| committer |   Kalle Valo <kvalo@codeaurora.org> | 2021-03-03 17:59:16 +0200 |
| commit | 295d4cd82b0181dd36b145fd535c13d623d7a335 (patch) | |
| tree | 23b2f904ff4c3a8accef646c1d93c9a0cc49d758 /drivers/net/wireless/intel/iwlwifi/pcie/rx.c | |
| parent | iwlwifi: fix ARCH=i386 compilation warnings (diff) | |
| download | linux-dev-295d4cd82b0181dd36b145fd535c13d623d7a335.tar.xz linux-dev-295d4cd82b0181dd36b145fd535c13d623d7a335.zip | |
iwlwifi: don't call netif_napi_add() with rxq->lock held (was Re: Lockdep warning in iwl_pcie_rx_handle())
We can't call netif_napi_add() with rxq-lock held, as there is a potential
for deadlock as spotted by lockdep (see below). rxq->lock is not
protecting anything over the netif_napi_add() codepath anyway, so let's
drop it just before calling into NAPI.
========================================================
WARNING: possible irq lock inversion dependency detected
5.12.0-rc1-00002-gbada49429032 #5 Not tainted
--------------------------------------------------------
irq/136-iwlwifi/565 just changed the state of lock:
ffff89f28433b0b0 (&rxq->lock){+.-.}-{2:2}, at: iwl_pcie_rx_handle+0x7f/0x960 [iwlwifi]
but this lock took another, SOFTIRQ-unsafe lock in the past:
(napi_hash_lock){+.+.}-{2:2}
and interrupts could create inverse lock ordering between them.
other info that might help us debug this:
Possible interrupt unsafe locking scenario:
CPU0 CPU1
---- ----
lock(napi_hash_lock);
local_irq_disable();
lock(&rxq->lock);
lock(napi_hash_lock);
<Interrupt>
lock(&rxq->lock);
*** DEADLOCK ***
1 lock held by irq/136-iwlwifi/565:
#0: ffff89f2b1440170 (sync_cmd_lockdep_map){+.+.}-{0:0}, at: iwl_pcie_irq_handler+0x5/0xb30
the shortest dependencies between 2nd lock and 1st lock:
-> (napi_hash_lock){+.+.}-{2:2} {
HARDIRQ-ON-W at:
lock_acquire+0x277/0x3d0
_raw_spin_lock+0x2c/0x40
netif_napi_add+0x14b/0x270
e1000_probe+0x2fe/0xee0 [e1000e]
local_pci_probe+0x42/0x90
pci_device_probe+0x10b/0x1c0
really_probe+0xef/0x4b0
driver_probe_device+0xde/0x150
device_driver_attach+0x4f/0x60
__driver_attach+0x9c/0x140
bus_for_each_dev+0x79/0xc0
bus_add_driver+0x18d/0x220
driver_register+0x5b/0xf0
do_one_initcall+0x5b/0x300
do_init_module+0x5b/0x21c
load_module+0x1dae/0x22c0
__do_sys_finit_module+0xad/0x110
do_syscall_64+0x33/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xae
SOFTIRQ-ON-W at:
lock_acquire+0x277/0x3d0
_raw_spin_lock+0x2c/0x40
netif_napi_add+0x14b/0x270
e1000_probe+0x2fe/0xee0 [e1000e]
local_pci_probe+0x42/0x90
pci_device_probe+0x10b/0x1c0
really_probe+0xef/0x4b0
driver_probe_device+0xde/0x150
device_driver_attach+0x4f/0x60
__driver_attach+0x9c/0x140
bus_for_each_dev+0x79/0xc0
bus_add_driver+0x18d/0x220
driver_register+0x5b/0xf0
do_one_initcall+0x5b/0x300
do_init_module+0x5b/0x21c
load_module+0x1dae/0x22c0
__do_sys_finit_module+0xad/0x110
do_syscall_64+0x33/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xae
INITIAL USE at:
lock_acquire+0x277/0x3d0
_raw_spin_lock+0x2c/0x40
netif_napi_add+0x14b/0x270
e1000_probe+0x2fe/0xee0 [e1000e]
local_pci_probe+0x42/0x90
pci_device_probe+0x10b/0x1c0
really_probe+0xef/0x4b0
driver_probe_device+0xde/0x150
device_driver_attach+0x4f/0x60
__driver_attach+0x9c/0x140
bus_for_each_dev+0x79/0xc0
bus_add_driver+0x18d/0x220
driver_register+0x5b/0xf0
do_one_initcall+0x5b/0x300
do_init_module+0x5b/0x21c
load_module+0x1dae/0x22c0
__do_sys_finit_module+0xad/0x110
do_syscall_64+0x33/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xae
}
... key at: [<ffffffffae84ef38>] napi_hash_lock+0x18/0x40
... acquired at:
_raw_spin_lock+0x2c/0x40
netif_napi_add+0x14b/0x270
_iwl_pcie_rx_init+0x1f4/0x710 [iwlwifi]
iwl_pcie_rx_init+0x1b/0x3b0 [iwlwifi]
iwl_trans_pcie_start_fw+0x2ac/0x6a0 [iwlwifi]
iwl_mvm_load_ucode_wait_alive+0x116/0x460 [iwlmvm]
iwl_run_init_mvm_ucode+0xa4/0x3a0 [iwlmvm]
iwl_op_mode_mvm_start+0x9ed/0xbf0 [iwlmvm]
_iwl_op_mode_start.isra.4+0x42/0x80 [iwlwifi]
iwl_opmode_register+0x71/0xe0 [iwlwifi]
iwl_mvm_init+0x34/0x1000 [iwlmvm]
do_one_initcall+0x5b/0x300
do_init_module+0x5b/0x21c
load_module+0x1dae/0x22c0
__do_sys_finit_module+0xad/0x110
do_syscall_64+0x33/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xae
[ ... lockdep output trimmed .... ]
Fixes: 25edc8f259c7106 ("iwlwifi: pcie: properly implement NAPI")
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Acked-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/nycvar.YFH.7.76.2103021134060.12405@cbobk.fhfr.pm
Diffstat (limited to 'drivers/net/wireless/intel/iwlwifi/pcie/rx.c')
| -rw-r--r-- | drivers/net/wireless/intel/iwlwifi/pcie/rx.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/rx.c b/drivers/net/wireless/intel/iwlwifi/pcie/rx.c index 42426e25cac6..2bec97133119 100644 --- a/drivers/net/wireless/intel/iwlwifi/pcie/rx.c +++ b/drivers/net/wireless/intel/iwlwifi/pcie/rx.c @@ -1129,6 +1129,8 @@ static int _iwl_pcie_rx_init(struct iwl_trans *trans) iwl_pcie_rx_init_rxb_lists(rxq); + spin_unlock_bh(&rxq->lock); + if (!rxq->napi.poll) { int (*poll)(struct napi_struct *, int) = iwl_pcie_napi_poll; @@ -1149,7 +1151,6 @@ static int _iwl_pcie_rx_init(struct iwl_trans *trans) napi_enable(&rxq->napi); } - spin_unlock_bh(&rxq->lock); } /* move the pool to the default queue and allocator ownerships */ |