Return-path: Received: from na3sys009aog107.obsmtp.com ([74.125.149.197]:33996 "EHLO na3sys009aog107.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754321Ab2I0THR (ORCPT ); Thu, 27 Sep 2012 15:07:17 -0400 From: Bing Zhao To: linux-wireless@vger.kernel.org Cc: Johannes Berg , "John W. Linville" , Sam Leffler , Amitkumar Karwar , Avinash Patil , Nishant Sarmukadam , Stone Piao , Frank Huang , Bing Zhao Subject: [PATCH v2 3/5] cfg80211: add support for flushing old scan results Date: Thu, 27 Sep 2012 11:59:12 -0700 Message-Id: <1348772354-15936-4-git-send-email-bzhao@marvell.com> (sfid-20120927_210726_308867_3C5A92A5) In-Reply-To: <1348772354-15936-1-git-send-email-bzhao@marvell.com> References: <1348772354-15936-1-git-send-email-bzhao@marvell.com> Sender: linux-wireless-owner@vger.kernel.org List-ID: From: Sam Leffler Add an NL80211_SCAN_FLAG_FLUSH flag that causes old bss cache entries to be flushed on scan completion. This is useful for collecting guaranteed fresh scan/survey results (e.g. on resume). Flushing only happens on successful completion of a scan; i.e. it does not happen if the scan is aborted/canceled. Signed-off-by: Sam Leffler Tested-by: Amitkumar Karwar Signed-off-by: Amitkumar Karwar Signed-off-by: Bing Zhao --- include/linux/nl80211.h | 2 ++ include/net/cfg80211.h | 4 ++++ net/wireless/nl80211.c | 1 + net/wireless/scan.c | 31 +++++++++++++++++++++++++++---- net/wireless/sme.c | 1 + 5 files changed, 35 insertions(+), 4 deletions(-) diff --git a/include/linux/nl80211.h b/include/linux/nl80211.h index e512baf..71400e7 100644 --- a/include/linux/nl80211.h +++ b/include/linux/nl80211.h @@ -3081,9 +3081,11 @@ enum nl80211_connect_failed_reason { * requests. * * @NL80211_SCAN_FLAG_LOW_PRIORITY: scan request has low priority + * @NL80211_SCAN_FLAG_FLUSH: flush cache before scanning */ enum nl80211_scan_flags { NL80211_SCAN_FLAG_LOW_PRIORITY = 1<<0, + NL80211_SCAN_FLAG_FLUSH = 1<<1, }; #endif /* __LINUX_NL80211_H */ diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h index ed659db..cc63a3a 100644 --- a/include/net/cfg80211.h +++ b/include/net/cfg80211.h @@ -995,9 +995,11 @@ struct cfg80211_ssid { * enum cfg80211_scan_flags - scan request control flags * * @CFG80211_SCAN_FLAG_LOW_PRIORITY: scan request has low priority + * @CFG80211_SCAN__FLAG_FLUSH: flush cache before scanning */ enum cfg80211_scan_flags { CFG80211_SCAN_FLAG_LOW_PRIORITY = NL80211_SCAN_FLAG_LOW_PRIORITY, + CFG80211_SCAN_FLAG_FLUSH = NL80211_SCAN_FLAG_FLUSH, }; /** @@ -1012,6 +1014,7 @@ enum cfg80211_scan_flags { * @flags: bit field of flags controlling operation * @rates: bitmap of rates to advertise for each band * @wiphy: the wiphy this was for + * @scan_start: time (in jiffies) when the scan started * @wdev: the wireless device to scan for * @aborted: (internal) scan request was notified as aborted * @no_cck: used to send probe requests at non CCK rate in 2GHz band @@ -1030,6 +1033,7 @@ struct cfg80211_scan_request { /* internal */ struct wiphy *wiphy; + unsigned long scan_start; bool aborted; bool no_cck; diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index e4312f6..7133477 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -4347,6 +4347,7 @@ static int nl80211_trigger_scan(struct sk_buff *skb, struct genl_info *info) request->wdev = wdev; request->wiphy = &rdev->wiphy; + request->scan_start = jiffies; rdev->scan_req = request; err = rdev->ops->scan(&rdev->wiphy, request); diff --git a/net/wireless/scan.c b/net/wireless/scan.c index 9730c98..392e5a9 100644 --- a/net/wireless/scan.c +++ b/net/wireless/scan.c @@ -20,6 +20,9 @@ #define IEEE80211_SCAN_RESULT_EXPIRE (30 * HZ) +static void __cfg80211_bss_expire(struct cfg80211_registered_device *dev, + int maxage, unsigned long expire_time); + void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev, bool leak) { struct cfg80211_scan_request *request; @@ -47,8 +50,15 @@ void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev, bool leak) if (request->aborted) nl80211_send_scan_aborted(rdev, wdev); - else + else { + if (request->flags & CFG80211_SCAN_FLAG_FLUSH) { + /* flush entries from previous scans */ + spin_lock_bh(&rdev->bss_lock); + __cfg80211_bss_expire(rdev, 0, request->scan_start); + spin_unlock_bh(&rdev->bss_lock); + } nl80211_send_scan_done(rdev, wdev); + } #ifdef CONFIG_CFG80211_WEXT if (wdev->netdev && !request->aborted) { @@ -198,7 +208,8 @@ static void __cfg80211_unlink_bss(struct cfg80211_registered_device *dev, } /* must hold dev->bss_lock! */ -void cfg80211_bss_expire(struct cfg80211_registered_device *dev) +static void __cfg80211_bss_expire(struct cfg80211_registered_device *dev, + int maxage, unsigned long expire_time) { struct cfg80211_internal_bss *bss, *tmp; bool expired = false; @@ -206,8 +217,14 @@ void cfg80211_bss_expire(struct cfg80211_registered_device *dev) list_for_each_entry_safe(bss, tmp, &dev->bss_list, list) { if (atomic_read(&bss->hold)) continue; - if (!time_after(jiffies, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE)) - continue; + if (maxage) { + if (!time_after(jiffies, bss->ts + maxage)) + continue; + } else { + if (!time_after(expire_time, bss->ts)) + continue; + } + __cfg80211_unlink_bss(dev, bss); expired = true; } @@ -216,6 +233,11 @@ void cfg80211_bss_expire(struct cfg80211_registered_device *dev) dev->bss_generation++; } +void cfg80211_bss_expire(struct cfg80211_registered_device *dev) +{ + __cfg80211_bss_expire(dev, IEEE80211_SCAN_RESULT_EXPIRE, 0); +} + const u8 *cfg80211_find_ie(u8 eid, const u8 *ies, int len) { while (len > 2 && ies[0] != eid) { @@ -962,6 +984,7 @@ int cfg80211_wext_siwscan(struct net_device *dev, creq->ssids = (void *)&creq->channels[n_channels]; creq->n_channels = n_channels; creq->n_ssids = 1; + creq->scan_start = jiffies; /* translate "Scan on frequencies" request */ i = 0; diff --git a/net/wireless/sme.c b/net/wireless/sme.c index 6f39cb8..dde1d47 100644 --- a/net/wireless/sme.c +++ b/net/wireless/sme.c @@ -138,6 +138,7 @@ static int cfg80211_conn_scan(struct wireless_dev *wdev) request->wdev = wdev; request->wiphy = &rdev->wiphy; + request->scan_start = jiffies; rdev->scan_req = request; -- 1.7.0.2