iwlwifi: pcie: move rx workqueue initialization to iwl_trans_pcie_alloc()

Work queues cannot be allocated when a mutex is held because the mutex
may be in use and that would make it sleep.  Doing so generates the
following splat with 4.13+:

[   19.513298] ======================================================
[   19.513429] WARNING: possible circular locking dependency detected
[   19.513557] 4.13.0-rc5+ #6 Not tainted
[   19.513638] ------------------------------------------------------
[   19.513767] cpuhp/0/12 is trying to acquire lock:
[   19.513867]  (&tz->lock){+.+.+.}, at: [<ffffffff924afebb>] thermal_zone_get_temp+0x5b/0xb0
[   19.514047]
[   19.514047] but task is already holding lock:
[   19.514166]  (cpuhp_state){+.+.+.}, at: [<ffffffff91cc4baa>] cpuhp_thread_fun+0x3a/0x210
[   19.514338]
[   19.514338] which lock already depends on the new lock.

This lock dependency already existed with previous kernel versions,
but it was not detected until commit 49dfe2a67797 ("cpuhotplug: Link
lock stacks for hotplug callbacks") was introduced.

Reported-by: David Weinehall <david.weinehall@intel.com>
Reported-by: Jiri Kosina <jikos@kernel.org>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/internal.h b/drivers/net/wireless/intel/iwlwifi/pcie/internal.h
index fa315d84e98e..a1ea9ef97ed9 100644
--- a/drivers/net/wireless/intel/iwlwifi/pcie/internal.h
+++ b/drivers/net/wireless/intel/iwlwifi/pcie/internal.h
@@ -787,6 +787,8 @@ int iwl_pci_fw_enter_d0i3(struct iwl_trans *trans);
 
 void iwl_pcie_enable_rx_wake(struct iwl_trans *trans, bool enable);
 
+void iwl_pcie_rx_allocator_work(struct work_struct *data);
+
 /* common functions that are used by gen2 transport */
 void iwl_pcie_apm_config(struct iwl_trans *trans);
 int iwl_pcie_prepare_card_hw(struct iwl_trans *trans);