Re: [PATCH 05/14] iwlwifi: report scan completion when abort fail

["Guy, Wey-Yi" <wey-yi.w.guy@intel.com>]

On Fri, 2010-09-10 at 07:26 -0700, Stanislaw Gruszka wrote:
> When we are not able to send abort command to firmware, notify mac80211
> that we complete scan, as we will newer do it lately. Check for all
> possible errors that low level sending command procedure does not check,
> to assure we catch all failures cases.
> 
> Patch fix one of the causes of wdev_cleanup_work warning reported at
> https://bugzilla.redhat.com/show_bug.cgi?id=593566
> 
> Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Acked-by: Wey-Yi W Guy <wey-yi.w.guy@intel.com>
> ---
>  drivers/net/wireless/iwlwifi/iwl-scan.c |  131 ++++++++++++++++---------------
>  1 files changed, 67 insertions(+), 64 deletions(-)
> 
> diff --git a/drivers/net/wireless/iwlwifi/iwl-scan.c b/drivers/net/wireless/iwlwifi/iwl-scan.c
> index ea33849..dbb07e8 100644
> --- a/drivers/net/wireless/iwlwifi/iwl-scan.c
> +++ b/drivers/net/wireless/iwlwifi/iwl-scan.c
> @@ -54,34 +54,83 @@
>  #define IWL_PASSIVE_DWELL_BASE      (100)
>  #define IWL_CHANNEL_TUNE_TIME       5
>  
> +static int iwl_send_scan_abort(struct iwl_priv *priv)
> +{
> +	int ret;
> +	struct iwl_rx_packet *pkt;
> +	struct iwl_host_cmd cmd = {
> +		.id = REPLY_SCAN_ABORT_CMD,
> +		.flags = CMD_WANT_SKB,
> +	};
>  
> +	/* Exit instantly with error when device is not ready
> +	 * to receive scan abort command or it does not perform
> +	 * hardware scan currently */
> +	if (!test_bit(STATUS_READY, &priv->status) ||
> +	    !test_bit(STATUS_GEO_CONFIGURED, &priv->status) ||
> +	    !test_bit(STATUS_SCAN_HW, &priv->status) ||
> +	    test_bit(STATUS_FW_ERROR, &priv->status) ||
> +	    test_bit(STATUS_EXIT_PENDING, &priv->status))
> +		return -EIO;
>  
> -/**
> - * iwl_scan_cancel - Cancel any currently executing HW scan
> - *
> - * NOTE: priv->mutex is not required before calling this function
> - */
> -int iwl_scan_cancel(struct iwl_priv *priv)
> -{
> -	if (!test_bit(STATUS_SCAN_HW, &priv->status)) {
> -		clear_bit(STATUS_SCANNING, &priv->status);
> -		return 0;
> +	ret = iwl_send_cmd_sync(priv, &cmd);
> +	if (ret)
> +		return ret;
> +
> +	pkt = (struct iwl_rx_packet *)cmd.reply_page;
> +	if (pkt->u.status != CAN_ABORT_STATUS) {
> +		/* The scan abort will return 1 for success or
> +		 * 2 for "failure".  A failure condition can be
> +		 * due to simply not being in an active scan which
> +		 * can occur if we send the scan abort before we
> +		 * the microcode has notified us that a scan is
> +		 * completed. */
> +		IWL_DEBUG_INFO(priv, "SCAN_ABORT ret %d.\n", pkt->u.status);
> +		ret = -EIO;
>  	}
>  
> -	if (test_bit(STATUS_SCANNING, &priv->status)) {
> -		if (!test_and_set_bit(STATUS_SCAN_ABORTING, &priv->status)) {
> -			IWL_DEBUG_SCAN(priv, "Queuing scan abort.\n");
> -			schedule_work(&priv->abort_scan);
> +	iwl_free_pages(priv, cmd.reply_page);
> +	return ret;
> +}
>  
> -		} else
> -			IWL_DEBUG_SCAN(priv, "Scan abort already in progress.\n");
> +static void iwl_do_scan_abort(struct iwl_priv *priv)
> +{
> +	int ret;
>  
> -		return test_bit(STATUS_SCANNING, &priv->status);
> +	lockdep_assert_held(&priv->mutex);
> +
> +	if (!test_bit(STATUS_SCANNING, &priv->status)) {
> +		IWL_DEBUG_SCAN(priv, "Not performing scan to abort\n");
> +		return;
>  	}
>  
> +	if (test_and_set_bit(STATUS_SCAN_ABORTING, &priv->status)) {
> +		IWL_DEBUG_SCAN(priv, "Scan abort in progress\n");
> +		return;
> +	}
> +
> +	ret = iwl_send_scan_abort(priv);
> +	if (ret) {
> +		IWL_DEBUG_SCAN(priv, "Send scan abort failed %d\n", ret);
> +		clear_bit(STATUS_SCANNING, &priv->status);
> +		clear_bit(STATUS_SCAN_HW, &priv->status);
> +		clear_bit(STATUS_SCAN_ABORTING, &priv->status);
> +		ieee80211_scan_completed(priv->hw, true);
> +	} else
> +		IWL_DEBUG_SCAN(priv, "Sucessfully send scan abort\n");
> +}
> +
> +/**
> + * iwl_scan_cancel - Cancel any currently executing HW scan
> + */
> +int iwl_scan_cancel(struct iwl_priv *priv)
> +{
> +	IWL_DEBUG_SCAN(priv, "Queuing abort scan\n");
> +	schedule_work(&priv->abort_scan);
>  	return 0;
>  }
>  EXPORT_SYMBOL(iwl_scan_cancel);
> +
>  /**
>   * iwl_scan_cancel_timeout - Cancel any currently executing HW scan
>   * @ms: amount of time to wait (in milliseconds) for scan to abort
> @@ -108,47 +157,6 @@ int iwl_scan_cancel_timeout(struct iwl_priv *priv, unsigned long ms)
>  }
>  EXPORT_SYMBOL(iwl_scan_cancel_timeout);
>  
> -static int iwl_send_scan_abort(struct iwl_priv *priv)
> -{
> -	int ret = 0;
> -	struct iwl_rx_packet *pkt;
> -	struct iwl_host_cmd cmd = {
> -		.id = REPLY_SCAN_ABORT_CMD,
> -		.flags = CMD_WANT_SKB,
> -	};
> -
> -	/* If there isn't a scan actively going on in the hardware
> -	 * then we are in between scan bands and not actually
> -	 * actively scanning, so don't send the abort command */
> -	if (!test_bit(STATUS_SCAN_HW, &priv->status)) {
> -		clear_bit(STATUS_SCAN_ABORTING, &priv->status);
> -		return 0;
> -	}
> -
> -	ret = iwl_send_cmd_sync(priv, &cmd);
> -	if (ret) {
> -		clear_bit(STATUS_SCAN_ABORTING, &priv->status);
> -		return ret;
> -	}
> -
> -	pkt = (struct iwl_rx_packet *)cmd.reply_page;
> -	if (pkt->u.status != CAN_ABORT_STATUS) {
> -		/* The scan abort will return 1 for success or
> -		 * 2 for "failure".  A failure condition can be
> -		 * due to simply not being in an active scan which
> -		 * can occur if we send the scan abort before we
> -		 * the microcode has notified us that a scan is
> -		 * completed. */
> -		IWL_DEBUG_INFO(priv, "SCAN_ABORT returned %d.\n", pkt->u.status);
> -		clear_bit(STATUS_SCAN_ABORTING, &priv->status);
> -		clear_bit(STATUS_SCAN_HW, &priv->status);
> -	}
> -
> -	iwl_free_pages(priv, cmd.reply_page);
> -
> -	return ret;
> -}
> -
>  /* Service response to REPLY_SCAN_CMD (0x80) */
>  static void iwl_rx_reply_scan(struct iwl_priv *priv,
>  			      struct iwl_rx_mem_buffer *rxb)
> @@ -527,15 +535,10 @@ static void iwl_bg_abort_scan(struct work_struct *work)
>  {
>  	struct iwl_priv *priv = container_of(work, struct iwl_priv, abort_scan);
>  
> -	if (!test_bit(STATUS_READY, &priv->status) ||
> -	    !test_bit(STATUS_GEO_CONFIGURED, &priv->status))
> -		return;
> -
>  	cancel_delayed_work(&priv->scan_check);
>  
>  	mutex_lock(&priv->mutex);
> -	if (test_bit(STATUS_SCAN_ABORTING, &priv->status))
> -		iwl_send_scan_abort(priv);
> +	iwl_do_scan_abort(priv);
>  	mutex_unlock(&priv->mutex);
>  }
>