2013-11-18 09:37:08

by Marek Puzyniak

Subject: [PATCH v2] cfg80211: fix dfs channel state after stopping AP

This can be called when a mode of operation that can supports
initiating radiation on a DFS channel leaves that channel to
ensure that if the mode of operation is started again on it
that it will require a new channel availability check.

Signed-off-by: Marek Puzyniak <[email protected]>
---
net/wireless/ap.c | 3 +++
net/wireless/chan.c | 39 +++++++++++++++++++++++++++++++++++++++
net/wireless/core.h | 11 +++++++++++
3 files changed, 53 insertions(+)

diff --git a/net/wireless/ap.c b/net/wireless/ap.c
index 324e8d8..9349773 100644
--- a/net/wireless/ap.c
+++ b/net/wireless/ap.c
@@ -26,6 +26,9 @@ static int __cfg80211_stop_ap(struct cfg80211_registered_device *rdev,

err = rdev_stop_ap(rdev, dev);
if (!err) {
+ if (cfg80211_chandef_dfs_required(wdev->wiphy, &wdev->preset_chandef))
+ cfg80211_leave_dfs_chandef(wdev->wiphy, &wdev->preset_chandef);
+
wdev->beacon_interval = 0;
wdev->channel = NULL;
wdev->ssid_len = 0;
diff --git a/net/wireless/chan.c b/net/wireless/chan.c
index 2ac4cac..bf85247 100644
--- a/net/wireless/chan.c
+++ b/net/wireless/chan.c
@@ -489,6 +489,45 @@ static bool cfg80211_chandef_dfs_available(struct wiphy *wiphy,
return r;
}

+static void cfg80211_leave_dfs_chans(struct wiphy *wiphy,
+ u32 center_freq,
+ u32 bandwidth)
+{
+ struct ieee80211_channel *c;
+ u32 freq, start_freq, end_freq;
+
+ start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
+ end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
+
+ for (freq = start_freq; freq <= end_freq; freq += 20) {
+ c = ieee80211_get_channel(wiphy, freq);
+ if (!c)
+ continue;
+ if (!(c->flags & IEEE80211_CHAN_RADAR))
+ continue;
+ if (c->dfs_state != NL80211_DFS_AVAILABLE)
+ continue;
+
+ cfg80211_set_chans_dfs_state(wiphy, freq, 20, NL80211_DFS_USABLE);
+ }
+}
+
+void cfg80211_leave_dfs_chandef(struct wiphy *wiphy,
+ struct cfg80211_chan_def *chandef)
+{
+ int width;
+
+ if (WARN_ON(!cfg80211_chandef_valid(chandef)))
+ return;
+
+ width = cfg80211_chandef_get_width(chandef);
+ cfg80211_leave_dfs_chans(wiphy, chandef->center_freq1, width);
+
+ if (!chandef->center_freq2)
+ return;
+
+ cfg80211_leave_dfs_chans(wiphy, chandef->center_freq2, width);
+}

static bool cfg80211_secondary_chans_ok(struct wiphy *wiphy,
u32 center_freq, u32 bandwidth,
diff --git a/net/wireless/core.h b/net/wireless/core.h
index 2888867..76dfe6b 100644
--- a/net/wireless/core.h
+++ b/net/wireless/core.h
@@ -401,6 +401,17 @@ void cfg80211_set_dfs_state(struct wiphy *wiphy,

void cfg80211_dfs_channels_update_work(struct work_struct *work);

+/**
+ * cfg80211_leave_dfs_chandef - Leaving dfs chandef
+ * @wiphy: the wiphy
+ * @chandef: chandef for the current channel
+ *
+ * This function is called when dfs chandef is being not used for different
+ * reasons. Change channels DFS_AVAILABLE to DFS_USABLE again. Leave channels
+ * DFS_UNAVAILABLE untouched.
+ */
+void cfg80211_leave_dfs_chandef(struct wiphy *wiphy,
+ struct cfg80211_chan_def *chandef);

static inline int
cfg80211_can_change_interface(struct cfg80211_registered_device *rdev,
--
1.8.1.2

2013-12-02 15:02:38

by Johannes Berg

Subject: Re: [PATCH v2] cfg80211: fix dfs channel state after stopping AP

On Mon, 2013-11-18 at 10:36 +0100, Marek Puzyniak wrote:
> This can be called when a mode of operation that can supports
> initiating radiation on a DFS channel leaves that channel to
> ensure that if the mode of operation is started again on it
> that it will require a new channel availability check.

Ugh, I don't understand - care to rephrase? Is this needed in 3.13?

johannes