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Message-ID: <4F5633E5.7040507@qca.qualcomm.com> (sfid-20120306_165744_407303_920066B0)
Date: Tue, 6 Mar 2012 17:57:25 +0200
From: Kalle Valo <kvalo@qca.qualcomm.com>
MIME-Version: 1.0
To: Vasanthakumar Thiagarajan <vthiagar@qca.qualcomm.com>
CC: <linux-wireless@vger.kernel.org>, <ath6kl-devel@qualcomm.com>
Subject: Re: [PATCH] ath6kl: Fix kernel panic while receiving fwlog during
 boot
References: <1331024980-1632-1-git-send-email-vthiagar@qca.qualcomm.com>
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On 03/06/2012 11:09 AM, Vasanthakumar Thiagarajan wrote:
> "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
> 
> Reported-by: Kalle Valo <kvalo@qca.qualcomm.com>
> Signed-off-by: Vasanthakumar Thiagarajan <vthiagar@qca.qualcomm.com>

Thanks, applied with these changes:

    kvalo: rename new function to ath6kl_debug_init_fs() and add a comment
    why it's needed

Kalle