Re: [PATCH 07/14] iwlwifi: rewrite scan completion

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

On Fri, 2010-09-10 at 07:26 -0700, Stanislaw Gruszka wrote:
> Assure (partially) we call ieee80211_scan_completed() only once when
> scan was requested from mac80211.
> 
> Code path that first clear STATUS_SCANNING bit is responsible to call
> ieee80211_scan_completed(). Before the call, we check if mac80211
> really request the scan.
> 
> Still persist some cases when we behave wrong, that will be addressed
> in the next patches.
> 
> 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 |   65 +++++++++++++++++++------------
>  1 files changed, 40 insertions(+), 25 deletions(-)
> 
> diff --git a/drivers/net/wireless/iwlwifi/iwl-scan.c b/drivers/net/wireless/iwlwifi/iwl-scan.c
> index 6d02f41..e65a98d 100644
> --- a/drivers/net/wireless/iwlwifi/iwl-scan.c
> +++ b/drivers/net/wireless/iwlwifi/iwl-scan.c
> @@ -93,6 +93,19 @@ static int iwl_send_scan_abort(struct iwl_priv *priv)
>  	return ret;
>  }
>  
> +static void iwl_complete_scan(struct iwl_priv *priv, bool aborted)
> +{
> +	/* check if scan was requested from mac80211 */
> +	if (priv->scan_request) {
> +		IWL_DEBUG_SCAN(priv, "Complete scan in mac80211\n");
> +		ieee80211_scan_completed(priv->hw, aborted);
> +	}
> +
> +	priv->is_internal_short_scan = false;
> +	priv->scan_vif = NULL;
> +	priv->scan_request = NULL;
> +}
> +
>  static void iwl_do_scan_abort(struct iwl_priv *priv)
>  {
>  	int ret;
> @@ -115,7 +128,7 @@ static void iwl_do_scan_abort(struct iwl_priv *priv)
>  		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);
> +		iwl_complete_scan(priv, true);
>  	} else
>  		IWL_DEBUG_SCAN(priv, "Sucessfully send scan abort\n");
>  }
> @@ -545,10 +558,11 @@ static void iwl_bg_scan_completed(struct work_struct *work)
>  {
>  	struct iwl_priv *priv =
>  	    container_of(work, struct iwl_priv, scan_completed);
> -	bool internal = false, aborted;
> +	bool aborted;
>  	struct iwl_rxon_context *ctx;
>  
> -	IWL_DEBUG_SCAN(priv, "SCAN complete scan\n");
> +	IWL_DEBUG_INFO(priv, "Completed %sscan.\n",
> +		       priv->is_internal_short_scan ? "internal short " : "");
>  
>  	cancel_delayed_work(&priv->scan_check);
>  
> @@ -558,37 +572,38 @@ static void iwl_bg_scan_completed(struct work_struct *work)
>  	if (aborted)
>  		IWL_DEBUG_INFO(priv, "Aborted scan completed.\n");
>  
> -	IWL_DEBUG_INFO(priv, "Setting scan to off\n");
> -
> -	clear_bit(STATUS_SCANNING, &priv->status);
> -
> -	if (priv->is_internal_short_scan) {
> -		priv->is_internal_short_scan = false;
> -		IWL_DEBUG_SCAN(priv, "internal short scan completed\n");
> -		internal = true;
> -	} else if (priv->scan_request) {
> -		priv->scan_request = NULL;
> -		priv->scan_vif = NULL;
> -		ieee80211_scan_completed(priv->hw, aborted);
> +	if (!test_and_clear_bit(STATUS_SCANNING, &priv->status)) {
> +		IWL_DEBUG_INFO(priv, "Scan already completed.\n");
> +		goto out;
>  	}
>  
> -	if (test_bit(STATUS_EXIT_PENDING, &priv->status))
> -		goto out;
> +	if (priv->is_internal_short_scan && !aborted) {
> +		int err;
>  
> -	if (internal && priv->scan_request) {
> -		int err = iwl_scan_initiate(priv, priv->scan_vif, false,
> -					priv->scan_request->channels[0]->band);
> +		/* Check if mac80211 requested scan during our internal scan */
> +		if (priv->scan_request == NULL)
> +			goto out_complete;
>  
> +		/* If so request a new scan */
> +		err = iwl_scan_initiate(priv, priv->scan_vif, false,
> +					priv->scan_request->channels[0]->band);
>  		if (err) {
>  			IWL_DEBUG_SCAN(priv,
>  				"failed to initiate pending scan: %d\n", err);
> -			priv->scan_request = NULL;
> -			priv->scan_vif = NULL;
> -			ieee80211_scan_completed(priv->hw, true);
> -		} else
> -			goto out;
> +			aborted = true;
> +			goto out_complete;
> +		}
> +
> +		goto out;
>  	}
>  
> +out_complete:
> +	iwl_complete_scan(priv, aborted);
> +
> +	/* Can we still talk to firmware ? */
> +	if (!iwl_is_ready_rf(priv))
> +		goto out;
> +
>  	/* Since setting the TXPOWER may have been deferred while
>  	 * performing the scan, fire one off */
>  	iwl_set_tx_power(priv, priv->tx_power_user_lmt, true);