[IWL4965] TX Power requested while scanning!

[IWL4965] TX Power requested while scanning!

[Paul Bolle]

0) Running v2.6.39-rc4 I ran into this (after a resume):

WARNING: at drivers/net/wireless/iwlegacy/iwl-4965.c:1128 iwl4965_send_tx_power+0x61/0x102 [iwl4965]()
Hardware name: [...]
TX Power requested while scanning!
Modules linked in: tcp_lp fuse cpufreq_ondemand acpi_cpufreq freq_table mperf ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 ip6table_filter ip6_tables ipv6 kvm_intel kvm uinput btusb arc4 snd_hda_codec_analog bluetooth ecb snd_hda_intel snd_hda_codec iwl4965 snd_hwdep snd_seq iwl_legacy snd_seq_device thinkpad_acpi mac80211 cfg80211 rfkill snd_pcm snd_timer iTCO_wdt snd i2c_i801 snd_page_alloc iTCO_vendor_support soundcore e1000e pcspkr microcode sdhci_pci sdhci firewire_ohci mmc_core firewire_core yenta_socket crc_itu_t i915 drm_kms_helper drm i2c_algo_bit i2c_core video [last unloaded: scsi_wait_scan]
Pid: 5723, comm: kworker/u:28 Not tainted 2.6.39-0.rc4.4.fc14.x86_64 #1
Call Trace:
 [<ffffffff8104e27b>] warn_slowpath_common+0x85/0x9d
 [<ffffffffa02782e0>] ? iwl4965_show_temperature+0x49/0x49 [iwl4965]
 [<ffffffff8104e336>] warn_slowpath_fmt+0x46/0x48
 [<ffffffffa027712f>] iwl4965_send_tx_power+0x61/0x102 [iwl4965]
 [<ffffffff81477e05>] ? mutex_lock+0x36/0x50
 [<ffffffffa0278337>] iwl4965_bg_txpower_work+0x57/0x73 [iwl4965]
 [<ffffffff810647f3>] process_one_work+0x18d/0x286
 [<ffffffff81065a5e>] worker_thread+0xfd/0x181
 [<ffffffff81065961>] ? manage_workers.clone.16+0x172/0x172
 [<ffffffff81069036>] kthread+0x82/0x8a
 [<ffffffff81480524>] kernel_thread_helper+0x4/0x10
 [<ffffffff81068fb4>] ? kthread_worker_fn+0x14b/0x14b
 [<ffffffff81480520>] ? gs_change+0x13/0x13

(2.6.39-0.rc4.4.fc14.x86_64 is not a Fedora blessed kernel, but a self
compiled "vanilla" kernel.) I have similar WARNINGs for rc2 and rc3 in
my log too.

1) The thing is that this triggers Fedora's "Automatic Bug Reporting
Tool", and is a bit noisy in dmesg and friends too, but everything seems
to be running just fine after that. I'm posting this from the session
that just triggered this! So why is this warning needed?


Paul Bolle

Re: [IWL4965] TX Power requested while scanning!

[Stanislaw Gruszka]

On Fri, Apr 22, 2011 at 08:56:22PM +0200, Paul Bolle wrote:
> 0) Running v2.6.39-rc4 I ran into this (after a resume):
> 
> WARNING: at drivers/net/wireless/iwlegacy/iwl-4965.c:1128 iwl4965_send_tx_power+0x61/0x102 [iwl4965]()
> Hardware name: [...]
> TX Power requested while scanning!
> Modules linked in: tcp_lp fuse cpufreq_ondemand acpi_cpufreq freq_table mperf ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 ip6table_filter ip6_tables ipv6 kvm_intel kvm uinput btusb arc4 snd_hda_codec_analog bluetooth ecb snd_hda_intel snd_hda_codec iwl4965 snd_hwdep snd_seq iwl_legacy snd_seq_device thinkpad_acpi mac80211 cfg80211 rfkill snd_pcm snd_timer iTCO_wdt snd i2c_i801 snd_page_alloc iTCO_vendor_support soundcore e1000e pcspkr microcode sdhci_pci sdhci firewire_ohci mmc_core firewire_core yenta_socket crc_itu_t i915 drm_kms_helper drm i2c_algo_bit i2c_core video [last unloaded: scsi_wait_scan]
> Pid: 5723, comm: kworker/u:28 Not tainted 2.6.39-0.rc4.4.fc14.x86_64 #1
> Call Trace:
>  [<ffffffff8104e27b>] warn_slowpath_common+0x85/0x9d
>  [<ffffffffa02782e0>] ? iwl4965_show_temperature+0x49/0x49 [iwl4965]
>  [<ffffffff8104e336>] warn_slowpath_fmt+0x46/0x48
>  [<ffffffffa027712f>] iwl4965_send_tx_power+0x61/0x102 [iwl4965]
>  [<ffffffff81477e05>] ? mutex_lock+0x36/0x50
>  [<ffffffffa0278337>] iwl4965_bg_txpower_work+0x57/0x73 [iwl4965]
>  [<ffffffff810647f3>] process_one_work+0x18d/0x286
>  [<ffffffff81065a5e>] worker_thread+0xfd/0x181
>  [<ffffffff81065961>] ? manage_workers.clone.16+0x172/0x172
>  [<ffffffff81069036>] kthread+0x82/0x8a
>  [<ffffffff81480524>] kernel_thread_helper+0x4/0x10
>  [<ffffffff81068fb4>] ? kthread_worker_fn+0x14b/0x14b
>  [<ffffffff81480520>] ? gs_change+0x13/0x13
> 
> (2.6.39-0.rc4.4.fc14.x86_64 is not a Fedora blessed kernel, but a self
> compiled "vanilla" kernel.) I have similar WARNINGs for rc2 and rc3 in
> my log too.
> 
> 1) The thing is that this triggers Fedora's "Automatic Bug Reporting
> Tool", and is a bit noisy in dmesg and friends too, but everything seems
> to be running just fine after that. I'm posting this from the session
> that just triggered this! So why is this warning needed?

Warning correctly indicate a bug. Please try below patch.

diff --git a/drivers/net/wireless/iwlegacy/iwl4965-base.c b/drivers/net/wireless/iwlegacy/iwl4965-base.c
index 58a2e63..46966e9 100644
--- a/drivers/net/wireless/iwlegacy/iwl4965-base.c
+++ b/drivers/net/wireless/iwlegacy/iwl4965-base.c
@@ -2988,15 +2988,15 @@ static void iwl4965_bg_txpower_work(struct work_struct *work)
 	struct iwl_priv *priv = container_of(work, struct iwl_priv,
 			txpower_work);
 
+	mutex_lock(&priv->mutex);
+
 	/* If a scan happened to start before we got here
 	 * then just return; the statistics notification will
 	 * kick off another scheduled work to compensate for
 	 * any temperature delta we missed here. */
 	if (test_bit(STATUS_EXIT_PENDING, &priv->status) ||
 	    test_bit(STATUS_SCANNING, &priv->status))
-		return;
-
-	mutex_lock(&priv->mutex);
+		goto out;
 
 	/* Regardless of if we are associated, we must reconfigure the
 	 * TX power since frames can be sent on non-radar channels while
@@ -3006,7 +3006,7 @@ static void iwl4965_bg_txpower_work(struct work_struct *work)
 	/* Update last_temperature to keep is_calib_needed from running
 	 * when it isn't needed... */
 	priv->last_temperature = priv->temperature;
-
+out:
 	mutex_unlock(&priv->mutex);
 }
 

Re: [IWL4965] TX Power requested while scanning!

[Paul Bolle]

On Tue, 2011-04-26 at 08:32 +0200, Stanislaw Gruszka wrote:
> Warning correctly indicate a bug. Please try below patch.
> 
> diff --git a/drivers/net/wireless/iwlegacy/iwl4965-base.c b/drivers/net/wireless/iwlegacy/iwl4965-base.c
> index 58a2e63..46966e9 100644
> --- a/drivers/net/wireless/iwlegacy/iwl4965-base.c
> +++ b/drivers/net/wireless/iwlegacy/iwl4965-base.c
> @@ -2988,15 +2988,15 @@ static void iwl4965_bg_txpower_work(struct work_struct *work)
>  	struct iwl_priv *priv = container_of(work, struct iwl_priv,
>  			txpower_work);
>  
> +	mutex_lock(&priv->mutex);
> +
>  	/* If a scan happened to start before we got here
>  	 * then just return; the statistics notification will
>  	 * kick off another scheduled work to compensate for
>  	 * any temperature delta we missed here. */
>  	if (test_bit(STATUS_EXIT_PENDING, &priv->status) ||
>  	    test_bit(STATUS_SCANNING, &priv->status))
> -		return;
> -
> -	mutex_lock(&priv->mutex);
> +		goto out;
>  
>  	/* Regardless of if we are associated, we must reconfigure the
>  	 * TX power since frames can be sent on non-radar channels while
> @@ -3006,7 +3006,7 @@ static void iwl4965_bg_txpower_work(struct work_struct *work)
>  	/* Update last_temperature to keep is_calib_needed from running
>  	 * when it isn't needed... */
>  	priv->last_temperature = priv->temperature;
> -
> +out:
>  	mutex_unlock(&priv->mutex);
>  }
>  

0) This (compiles and) runs without apparent problems. I haven't seen
this WARNING with this patch applied. But please note that I actually
haven't seen that WARNING with (unpatched) rc4 since reporting it (last
Friday).

1) So feel free to add a "Reported-by:" tag and, perhaps, a "Tested-by:"
tag too.


Paul Bolle