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authorVasanthakumar Thiagarajan <vthiagar@qca.qualcomm.com>2012-03-06 14:39:40 +0530
committerKalle Valo <kvalo@qca.qualcomm.com>2012-03-06 17:53:54 +0200
commit068a4633bf42501db3ec934beff07cd50c1b7e9d (patch)
treece9f87c4caa333517d2c77d7b0c3a85dbe820c2d /drivers/net/wireless/ath/ath6kl/debug.c
parent05e5bd0f3daddb0368a433af5b58be68c62dc365 (diff)
ath6kl: Fix kernel panic while receiving fwlog during boot
"ath6kl: Defer wiphy and netdev registration till the end of ath6kl_core_init()" causes kernel panic by accessing the unallocated debug resources during boot time. To fix this, split the debug initialization funtion into two, one initializes the debug resource and the other takes care of debugfs initialization. When this issue shows up the kernel crash dump would look like ath6kl_debug_fwlog_event+0x9c/0x10a [<c10666c9>] register_lock_class+0x57/0x288 [<c1065cd3>] ? trace_hardirqs_on+0xb/0xd [<f801f4c9>] ? ath6kl_debug_fwlog_event+0x9c/0x10a [<c1066a8a>] __lock_acquire+0x96/0xbe5 [<c106007b>] ? alarmtimer_suspend+0x80/0x127 [<c10258da>] ? vprintk+0x394/0x3b1 [<f801f4c9>] ? ath6kl_debug_fwlog_event+0x9c/0x10a [<c10676b3>] lock_acquire+0xda/0xf9 [<f801f4c9>] ? ath6kl_debug_fwlog_event+0x9c/0x10a [<c1532ce3>] _raw_spin_lock+0x28/0x58 [<f801f4c9>] ? ath6kl_debug_fwlog_event+0x9c/0x10a [<f801f4c9>] ath6kl_debug_fwlog_event+0x9c/0x10a [<f80310a4>] ath6kl_wmi_control_rx+0x69d/0xb50 [ath6kl_core] [<f802d2e1>] ? ath6kl_rx+0x3c/0x839 [ath6kl_core] [<f802d35d>] ath6kl_rx+0xb8/0x839 [ath6kl_core] [<c104b81e>] ? local_clock+0x2d/0x4e [<c102a0af>] ? _local_bh_enable_ip+0x94/0x98 [<f802bfc0>] ? ath6kl_alloc_amsdu_rxbuf+0xb7/0xb7 [<f8023b28>] ath6kl_htc_rxmsg_pending_handler+0x891/0x988 [ath6kl_core] [<f802bf00>] ? ath6kl_refill_amsdu_rxbufs+0x89/0x92 [<f802d2a5>] ? aggr_timeout+0xed/0xed [ath6kl_core] [<f802bfc0>] ? ath6kl_alloc_amsdu_rxbuf+0xb7/0xb7 [<f802c420>] ? ath6kl_tx_complete+0x376/0x376 [ath6kl_core] [<f8020e92>] ath6kl_hif_intr_bh_handler+0xf7/0x33e [<c138ab00>] ? mmc_host_disable+0x15/0x3a [<f8123b5c>] ath6kl_sdio_irq_handler+0x3c/0x90 [ath6kl_sdio] [<c1392f56>] sdio_irq_thread+0xb6/0x29c [<c1392ea0>] ? sdio_claim_irq+0x1cb/0x1cb [<c103d4c0>] kthread+0x67/0x6c [<c103d459>] ? __init_kthread_worker+0x42/0x42 [<c153903a>] kernel_thread_helper+0x6/0xd BUG: unable to handle kernel NULL pointer dereference at EIP: [<f801f4d4>] ath6kl_debug_fwlog_event+0xa7/0x10a kvalo: rename new function to ath6kl_debug_init_fs() and add a comment why it's needed Reported-by: Kalle Valo <kvalo@qca.qualcomm.com> Signed-off-by: Vasanthakumar Thiagarajan <vthiagar@qca.qualcomm.com> Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
Diffstat (limited to 'drivers/net/wireless/ath/ath6kl/debug.c')
-rwxr-xr-xdrivers/net/wireless/ath/ath6kl/debug.c10
1 files changed, 9 insertions, 1 deletions
diff --git a/drivers/net/wireless/ath/ath6kl/debug.c b/drivers/net/wireless/ath/ath6kl/debug.c
index 28b516ff3d59..645f923f79b5 100755
--- a/drivers/net/wireless/ath/ath6kl/debug.c
+++ b/drivers/net/wireless/ath/ath6kl/debug.c
@@ -1722,7 +1722,7 @@ static const struct file_operations fops_power_params = {
.llseek = default_llseek,
};
-int ath6kl_debug_init(struct ath6kl *ar)
+void ath6kl_debug_init(struct ath6kl *ar)
{
skb_queue_head_init(&ar->debug.fwlog_queue);
init_completion(&ar->debug.fwlog_completion);
@@ -1732,7 +1732,15 @@ int ath6kl_debug_init(struct ath6kl *ar)
* value from the firmware.
*/
ar->debug.fwlog_mask = 0;
+}
+/*
+ * Initialisation needs to happen in two stages as fwlog events can come
+ * before cfg80211 is initialised, and debugfs depends on cfg80211
+ * initialisation.
+ */
+int ath6kl_debug_init_fs(struct ath6kl *ar)
+{
ar->debugfs_phy = debugfs_create_dir("ath6kl",
ar->wiphy->debugfsdir);
if (!ar->debugfs_phy)