[PATCH 08/10] iwlwifi: mvm: take the UCODE_DOWN reference when resuming

From: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
To: linux-wireless@vger.kernel.org
Cc: Luciano Coelho <luciano.coelho@intel.com>,
	Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Subject: [PATCH 08/10] iwlwifi: mvm: take the UCODE_DOWN reference when resuming
Date: Thu, 21 May 2015 22:53:08 +0300	[thread overview]
Message-ID: <1432237990-5890-8-git-send-email-emmanuel.grumbach@intel.com> (raw)
In-Reply-To: <1432237819.26813.4.camel@intel.com>

From: Luciano Coelho <luciano.coelho@intel.com>

The __iwl_mvm_resume() function always returns 1, which causes
mac80211 to do a reconfig with IEEE80211_RECONFIG_TYPE_RESTART.  This
type of reconfig calls iwl_mvm_restart_complete(), where we unref the
IWL_MVM_REF_UCODE_DOWN, so we should always take the reference in this
case.

This prevents this kind of warning from happening:

[40026.103025] WARNING: at /root/iwlwifi/iwlwifi-stack-dev/drivers/net/wireless/iwlwifi/mvm/mac80211.c:236 iwl_mvm_unref+0xc9/0xd0 [iwlmvm]()
[40026.105145] Modules linked in: iwlmvm(O) iwlwifi(O) mac80211(O) cfg80211(O) compat(O) ctr ccm arc4 autofs4 snd_hda_codec_hdmi snd_hda_codec_idt joydev coretemp kvm_intel kvm aesni_intel ablk_helper cryptd lrw aes_i586 snd_hda_intel xts snd_hda_codec gf128mul snd_hwdep snd_pcm snd_seq_midi dell_wmi snd_rawmidi sparse_keymap snd_seq_midi_event snd_seq uvcvideo dell_laptop videobuf2_core dcdbas microcode videodev psmouse snd_timer videobuf2_vmalloc videobuf2_memops serio_raw snd_seq_device btusb i915 snd bluetooth lpc_ich drm_kms_helper soundcore snd_page_alloc drm i2c_algo_bit wmi parport_pc ppdev video binfmt_misc rpcsec_gss_krb5 nfsd mac_hid nfs_acl nfsv4 auth_rpcgss nfs fscache lockd sunrpc msdos lp parport sdhci_pci sdhci ahci libahci e1000e mmc_core ptp pps_core [last unloaded: compat]
[40026.117640] CPU: 2 PID: 3827 Comm: bash Tainted: G        W  O 3.10.29-dev #1
[40026.120216] Hardware name: Dell Inc. Latitude E6430/0CPWYR, BIOS A09 12/13/2012
[40026.122815]  f8effd18 f8effd18 e740fd18 c168aa62 e740fd40 c103a824 c1871238 f8effd18
[40026.125527]  000000ec f8ec79c9 f8ec79c9 d5d29ba4 d5d2a20c 00000000 e740fd50 c103a862
[40026.128209]  00000009 00000000 e740fd7c f8ec79c9 f1c591c4 00000400 00000000 f8efb490
[40026.130886] Call Trace:
[40026.133506]  [<c168aa62>] dump_stack+0x16/0x18
[40026.136115]  [<c103a824>] warn_slowpath_common+0x64/0x80
[40026.138727]  [<f8ec79c9>] ? iwl_mvm_unref+0xc9/0xd0 [iwlmvm]
[40026.141319]  [<f8ec79c9>] ? iwl_mvm_unref+0xc9/0xd0 [iwlmvm]
[40026.143881]  [<c103a862>] warn_slowpath_null+0x22/0x30
[40026.146453]  [<f8ec79c9>] iwl_mvm_unref+0xc9/0xd0 [iwlmvm]
[40026.149030]  [<f8ec7a4d>] iwl_mvm_mac_reconfig_complete+0x7d/0x210 [iwlmvm]
[40026.151645]  [<f8b74b20>] ? ftrace_raw_event_drv_reconfig_complete+0xc0/0xe0 [mac80211]
[40026.154291]  [<f8b6769e>] ieee80211_reconfig+0x28e/0x2620 [mac80211]
[40026.156920]  [<c10ef0ea>] ? ring_buffer_unlock_commit+0xba/0x100
[40026.159585]  [<f8b4a04d>] ieee80211_resume+0x6d/0x80 [mac80211]
[40026.162206]  [<f8a79722>] wiphy_resume+0x72/0x260 [cfg80211]
[40026.164799]  [<c141e2e7>] ? device_resume+0x57/0x150
[40026.167425]  [<f8a796b0>] ? wiphy_suspend+0x710/0x710 [cfg80211]
[40026.170075]  [<c141e26e>] dpm_run_callback+0x2e/0x50
[40026.172695]  [<c141e321>] device_resume+0x91/0x150
[40026.175334]  [<c141f636>] dpm_resume+0xf6/0x200
[40026.177922]  [<c141f920>] dpm_resume_end+0x10/0x20
[40026.180489]  [<c108d9f7>] suspend_devices_and_enter+0x177/0x480
[40026.183037]  [<c168646a>] ? printk+0x4d/0x4f
[40026.185559]  [<c108de76>] pm_suspend+0x176/0x210
[40026.188065]  [<c108ca5d>] state_store+0x5d/0xb0
[40026.190581]  [<c108ca00>] ? wakeup_count_show+0x50/0x50
[40026.193052]  [<c13208db>] kobj_attr_store+0x1b/0x30
[40026.195608]  [<c11e3a4b>] sysfs_write_file+0xab/0x100
[40026.198055]  [<c11e39a0>] ? sysfs_poll+0xa0/0xa0
[40026.200469]  [<c1179655>] vfs_write+0xa5/0x1c0
[40026.202893]  [<c1179af7>] SyS_write+0x57/0xa0
[40026.205245]  [<c1699ec1>] sysenter_do_call+0x12/0x32
[40026.207619] ---[ end trace db1d5a72a0381b0a ]---

Signed-off-by: Luciano Coelho <luciano.coelho@intel.com>
Reviewed-by: EliadX Peller <eliad@wizery.com>
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
---
 drivers/net/wireless/iwlwifi/mvm/d3.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/iwlwifi/mvm/d3.c b/drivers/net/wireless/iwlwifi/mvm/d3.c
index 42dadaf..91ca8df 100644
--- a/drivers/net/wireless/iwlwifi/mvm/d3.c
+++ b/drivers/net/wireless/iwlwifi/mvm/d3.c
@@ -1917,6 +1917,14 @@ out:
 	/* return 1 to reconfigure the device */
 	set_bit(IWL_MVM_STATUS_IN_HW_RESTART, &mvm->status);
 	set_bit(IWL_MVM_STATUS_D3_RECONFIG, &mvm->status);
+
+	/* We always return 1, which causes mac80211 to do a reconfig
+	 * with IEEE80211_RECONFIG_TYPE_RESTART.  This type of
+	 * reconfig calls iwl_mvm_restart_complete(), where we unref
+	 * the IWL_MVM_REF_UCODE_DOWN, so we need to take the
+	 * reference here.
+	 */
+	iwl_mvm_ref(mvm, IWL_MVM_REF_UCODE_DOWN);
 	return 1;
 }
 
@@ -2023,7 +2031,6 @@ static int iwl_mvm_d3_test_release(struct inode *inode, struct file *file)
 	__iwl_mvm_resume(mvm, true);
 	rtnl_unlock();
 	iwl_abort_notification_waits(&mvm->notif_wait);
-	iwl_mvm_ref(mvm, IWL_MVM_REF_UCODE_DOWN);
 	ieee80211_restart_hw(mvm->hw);
 
 	/* wait for restart and disconnect all interfaces */
-- 
2.1.4

