From d9b8396a52b4e857263eeb9e1eba474ea11c19bf Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Thu, 13 Feb 2014 17:16:10 +0100 Subject: [PATCH] cfg80211: document sched_scan_stop synchronous behaviour Due to userspace assumptions, the sched_scan_stop operation must be synchronous, i.e. once it returns a new scheduled scan must be able to start immediately. Document this in the API. Signed-off-by: Johannes Berg --- include/net/cfg80211.h | 7 ++++++- include/uapi/linux/nl80211.h | 5 +++-- 2 files changed, 9 insertions(+), 3 deletions(-) diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h index c89a5b5bd103..7c9fe4b05927 100644 --- a/include/net/cfg80211.h +++ b/include/net/cfg80211.h @@ -2206,7 +2206,12 @@ struct cfg80211_qos_map { * @set_cqm_txe_config: Configure connection quality monitor TX error * thresholds. * @sched_scan_start: Tell the driver to start a scheduled scan. - * @sched_scan_stop: Tell the driver to stop an ongoing scheduled scan. + * @sched_scan_stop: Tell the driver to stop an ongoing scheduled scan. This + * call must stop the scheduled scan and be ready for starting a new one + * before it returns, i.e. @sched_scan_start may be called immediately + * after that again and should not fail in that case. The driver should + * not call cfg80211_sched_scan_stopped() for a requested stop (when this + * method returns 0.) * * @mgmt_frame_register: Notify driver that a management frame type was * registered. Note that this callback may not sleep, and cannot run diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h index 47d7087513e0..81481cff1dc1 100644 --- a/include/uapi/linux/nl80211.h +++ b/include/uapi/linux/nl80211.h @@ -303,8 +303,9 @@ * passed, all channels allowed for the current regulatory domain * are used. Extra IEs can also be passed from the userspace by * using the %NL80211_ATTR_IE attribute. - * @NL80211_CMD_STOP_SCHED_SCAN: stop a scheduled scan. Returns -ENOENT - * if scheduled scan is not running. + * @NL80211_CMD_STOP_SCHED_SCAN: stop a scheduled scan. Returns -ENOENT if + * scheduled scan is not running. The caller may assume that as soon + * as the call returns, it is safe to start a new scheduled scan again. * @NL80211_CMD_SCHED_SCAN_RESULTS: indicates that there are scheduled scan * results available. * @NL80211_CMD_SCHED_SCAN_STOPPED: indicates that the scheduled scan has -- 2.20.1