From 15dbf1b7b7b6ba6e5159dde60e111f617b2c54ea Mon Sep 17 00:00:00 2001 From: Bill Moss Date: Tue, 6 May 2008 11:05:15 +0800 Subject: [PATCH] iwl3945: do not delay hardware scan if it is a direct scan iwl3945 <---> mac80211 <----> wpa_supplicant <---> NetworkManager When a hardware scan is completed and another scan is requested in less than two seconds, iwlwifi will not do the second scan and will pass the error code -EAGAIN back to mac80211 where it quickly dies. The error code is not passed along to the calling program wpa_supplicant. After a timeout, wpa_supplicant will just give up but it will not know why the scan failed. This is a weakness in the design. I ran into this issue when I was trying to figure out why it takes more an a minute for NetworkManager to connect after Networking has been disabled and then re-enabled. I found a good deal of unnecessary work being done because mac80211 requests authentication when the interface is not configured, the ANY mode. I created an experimental passive (NOTANY) mode for mac80211 to eliminate this case. Then NetworkManager became so fast that I ran into the iwlwifi 2 second delay next scan issue which we are discussing. The patch resolves the problem by bypassing the delay if the scan request is a direct scan. It should do less harm to the hardware. Signed-off-by: Bill Moss Signed-off-by: Zhu Yi Signed-off-by: John W. Linville --- drivers/net/wireless/iwlwifi/iwl3945-base.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/net/wireless/iwlwifi/iwl3945-base.c b/drivers/net/wireless/iwlwifi/iwl3945-base.c index f021eba41e6a..4baa185ba500 100644 --- a/drivers/net/wireless/iwlwifi/iwl3945-base.c +++ b/drivers/net/wireless/iwlwifi/iwl3945-base.c @@ -7087,9 +7087,10 @@ static int iwl3945_mac_hw_scan(struct ieee80211_hw *hw, u8 *ssid, size_t len) rc = -EAGAIN; goto out_unlock; } - /* if we just finished scan ask for delay */ - if (priv->last_scan_jiffies && time_after(priv->last_scan_jiffies + - IWL_DELAY_NEXT_SCAN, jiffies)) { + /* if we just finished scan ask for delay for a broadcast scan */ + if ((len == 0) && priv->last_scan_jiffies && + time_after(priv->last_scan_jiffies + IWL_DELAY_NEXT_SCAN, + jiffies)) { rc = -EAGAIN; goto out_unlock; } -- 2.34.1