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From: Emmanuel Grumbach <egrumbach@gmail.com>
To: linux-wireless@vger.kernel.org
Cc: Luciano Coelho <luciano.coelho@intel.com>,
	Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Subject: [PATCH 03/25] iwlwifi: mvm: hold the rtnl when resuming from a d3 test
Date: Wed, 29 Oct 2014 13:50:24 +0200
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From: Luciano Coelho <luciano.coelho@intel.com>

We use ieee80211_iter_keys() which requires the rtnl to be held.  If
we don't lock the rtnl, like we do when we suspend during a d3 test,
we get the following splat:

 RTNL: assertion failed at net/mac80211/key.c (566)
 CPU: 1 PID: 26529 Comm: cat Tainted: G        W  O 3.10.29-dev #1
 Hardware name: Dell Inc. Latitude E6430/0CPWYR, BIOS A09 12/13/2012
  e7b15008 e7b15008 e68adc1c c168aa62 e68adc54 f91f20b6 f923700c f9236fd8
  00000236 00000000 ece23874 00000000 f94941e0 00000000 e43b8e48 e7b15008
  00000000 e8b69e78 e68adcc0 f9493ab9 e68adc68 00000000 e43b8e48 e7b15008
 Call Trace:
  [<c168aa62>] dump_stack+0x16/0x18
  [<f91f20b6>] ieee80211_iter_keys+0x166/0x170 [mac80211]
  [<f94941e0>] ? iwl_mvm_query_wakeup_reasons+0x5f0/0x5f0 [iwlmvm]
  [<f9493ab9>] iwl_mvm_setup_connection_keep.isra.5+0x99/0x1d0 [iwlmvm]
  [<f9165e28>] ? cfg80211_report_wowlan_wakeup+0x308/0x510 [cfg80211]
  [<f9493fe5>] iwl_mvm_query_wakeup_reasons+0x3f5/0x5f0 [iwlmvm]
  [<c116125a>] ? init_object+0x3a/0x70
  [<f8a5b8ee>] ? iwl_trans_pcie_d3_resume+0x1be/0x3a0 [iwlwifi]
  [<f94956da>] __iwl_mvm_resume+0x14a/0x180 [iwlmvm]
  [<f9495736>] iwl_mvm_d3_test_release+0x26/0xc0 [iwlmvm]
  [<c117a64d>] __fput+0xad/0x210
  [<c117a7bd>] ____fput+0xd/0x10
  [<c10601a1>] task_work_run+0x81/0xb0
  [<c1040fa5>] do_exit+0x255/0xac0
  [<c104e511>] ? dequeue_signal+0x31/0x1a0
  [<c1041888>] do_group_exit+0x38/0xa0
  [<c10a6cfb>] ? trace_hardirqs_on+0xb/0x10
  [<c1051c31>] get_signal_to_deliver+0x1e1/0x8e0
  [<c104bd52>] ? try_to_del_timer_sync+0x42/0x60
  [<c104bd70>] ? try_to_del_timer_sync+0x60/0x60
  [<c168dc82>] ? schedule_timeout+0x102/0x2a0
  [<c10011ba>] do_signal+0x3a/0x8e0
  [<c104b190>] ? __internal_add_timer+0xb0/0xb0
  [<c168de7a>] ? schedule_timeout_interruptible+0x1a/0x20
  [<c104ce39>] ? msleep_interruptible+0x39/0x40
  [<f94939a9>] ? iwl_mvm_d3_test_read+0x49/0x70 [iwlmvm]
  [<c11797fc>] ? vfs_read+0x8c/0x160
  [<c11243af>] ? SyS_fadvise64_64+0x15f/0x2b0
  [<f9493960>] ? iwl_mvm_wowlan_program_keys+0x4a0/0x4a0 [iwlmvm]
  [<c1179a57>] ? SyS_read+0x57/0xa0
  [<c1001acf>] do_notify_resume+0x6f/0xa0
  [<c1692500>] work_notifysig+0x29/0x31

Fix this by hold the rtnl lock when calling __iwl_mvm_resume() in the
d3 test wake up path.

Signed-off-by: Luciano Coelho <luciano.coelho@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
---
 drivers/net/wireless/iwlwifi/mvm/d3.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/wireless/iwlwifi/mvm/d3.c b/drivers/net/wireless/iwlwifi/mvm/d3.c
index c17be0f..5b26922 100644
--- a/drivers/net/wireless/iwlwifi/mvm/d3.c
+++ b/drivers/net/wireless/iwlwifi/mvm/d3.c
@@ -1741,7 +1741,9 @@ static int iwl_mvm_d3_test_release(struct inode *inode, struct file *file)
 	int remaining_time = 10;
 
 	mvm->d3_test_active = false;
+	rtnl_lock();
 	__iwl_mvm_resume(mvm, true);
+	rtnl_unlock();
 	iwl_abort_notification_waits(&mvm->notif_wait);
 	ieee80211_restart_hw(mvm->hw);
 
-- 
1.9.1