From 5037a00992e5fcb3d8509964313565a3dab6697c Mon Sep 17 00:00:00 2001
From: Sunil Dutt <usdutt@qti.qualcomm.com>
Date: Thu, 25 Jan 2018 17:13:37 +0200
Subject: [PATCH] nl80211: Introduce scan flags to emphasize requested scan behavior
Git-commit: 5037a00992e5fcb3d8509964313565a3dab6697c
Patch-mainline: v4.17-rc1
References: FATE#326294
This commit defines new scan flags (LOW_SPAN, LOW_POWER, HIGH_LATENCY)
to emphasize the requested scan behavior for the driver. These flags
are optional and are mutually exclusive. The implementation of the
respective functionality can be driver/hardware specific.
These flags can be used to control the compromise between how long
a scan takes, how much power it uses, and high accurate/complete
the scan is in finding the BSSs.
Signed-off-by: Sunil Dutt <usdutt@qti.qualcomm.com>
Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
include/uapi/linux/nl80211.h | 28 +++++++++++++++++++++++++++-
net/wireless/nl80211.c | 13 +++++++++++--
2 files changed, 38 insertions(+), 3 deletions(-)
diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index c587a61c32bf..6f60503fa617 100644
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -4945,6 +4945,9 @@ enum nl80211_feature_flags {
* probe request tx deferral and suppression
* @NL80211_EXT_FEATURE_MFP_OPTIONAL: Driver supports the %NL80211_MFP_OPTIONAL
* value in %NL80211_ATTR_USE_MFP.
+ * @NL80211_EXT_FEATURE_LOW_SPAN_SCAN: Driver supports low span scan.
+ * @NL80211_EXT_FEATURE_LOW_POWER_SCAN: Driver supports low power scan.
+ * @NL80211_EXT_FEATURE_HIGH_ACCURACY_SCAN: Driver supports high accuracy scan.
*
* @NUM_NL80211_EXT_FEATURES: number of extended features.
* @MAX_NL80211_EXT_FEATURES: highest extended feature index.
@@ -4972,6 +4975,9 @@ enum nl80211_ext_feature_index {
NL80211_EXT_FEATURE_OCE_PROBE_REQ_HIGH_TX_RATE,
NL80211_EXT_FEATURE_OCE_PROBE_REQ_DEFERRAL_SUPPRESSION,
NL80211_EXT_FEATURE_MFP_OPTIONAL,
+ NL80211_EXT_FEATURE_LOW_SPAN_SCAN,
+ NL80211_EXT_FEATURE_LOW_POWER_SCAN,
+ NL80211_EXT_FEATURE_HIGH_ACCURACY_SCAN,
/* add new features before the definition below */
NUM_NL80211_EXT_FEATURES,
@@ -5032,6 +5038,10 @@ enum nl80211_timeout_reason {
* of NL80211_CMD_TRIGGER_SCAN and NL80211_CMD_START_SCHED_SCAN
* requests.
*
+ * NL80211_SCAN_FLAG_LOW_SPAN, NL80211_SCAN_FLAG_LOW_POWER, and
+ * NL80211_SCAN_FLAG_HIGH_ACCURACY flags are exclusive of each other, i.e., only
+ * one of them can be used in the request.
+ *
* @NL80211_SCAN_FLAG_LOW_PRIORITY: scan request has low priority
* @NL80211_SCAN_FLAG_FLUSH: flush cache before scanning
* @NL80211_SCAN_FLAG_AP: force a scan even if the interface is configured
@@ -5059,7 +5069,20 @@ enum nl80211_timeout_reason {
* and suppression (if it has received a broadcast Probe Response frame,
* Beacon frame or FILS Discovery frame from an AP that the STA considers
* a suitable candidate for (re-)association - suitable in terms of
- * SSID and/or RSSI
+ * SSID and/or RSSI.
+ * @NL80211_SCAN_FLAG_LOW_SPAN: Span corresponds to the total time taken to
+ * accomplish the scan. Thus, this flag intends the driver to perform the
+ * scan request with lesser span/duration. It is specific to the driver
+ * implementations on how this is accomplished. Scan accuracy may get
+ * impacted with this flag.
+ * @NL80211_SCAN_FLAG_LOW_POWER: This flag intends the scan attempts to consume
+ * optimal possible power. Drivers can resort to their specific means to
+ * optimize the power. Scan accuracy may get impacted with this flag.
+ * @NL80211_SCAN_FLAG_HIGH_ACCURACY: Accuracy here intends to the extent of scan
+ * results obtained. Thus HIGH_ACCURACY scan flag aims to get maximum
+ * possible scan results. This flag hints the driver to use the best
+ * possible scan configuration to improve the accuracy in scanning.
+ * Latency and power use may get impacted with this flag.
*/
enum nl80211_scan_flags {
NL80211_SCAN_FLAG_LOW_PRIORITY = 1<<0,
@@ -5070,6 +5093,9 @@ enum nl80211_scan_flags {
NL80211_SCAN_FLAG_ACCEPT_BCAST_PROBE_RESP = 1<<5,
NL80211_SCAN_FLAG_OCE_PROBE_REQ_HIGH_TX_RATE = 1<<6,
NL80211_SCAN_FLAG_OCE_PROBE_REQ_DEFERRAL_SUPPRESSION = 1<<7,
+ NL80211_SCAN_FLAG_LOW_SPAN = 1<<8,
+ NL80211_SCAN_FLAG_LOW_POWER = 1<<9,
+ NL80211_SCAN_FLAG_HIGH_ACCURACY = 1<<10,
};
/**
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index ab0c687d0c44..dd249ec9f228 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -6715,8 +6715,17 @@ nl80211_check_scan_flags(struct wiphy *wiphy, struct wireless_dev *wdev,
*flags = nla_get_u32(attrs[NL80211_ATTR_SCAN_FLAGS]);
- if ((*flags & NL80211_SCAN_FLAG_LOW_PRIORITY) &&
- !(wiphy->features & NL80211_FEATURE_LOW_PRIORITY_SCAN))
+ if (((*flags & NL80211_SCAN_FLAG_LOW_PRIORITY) &&
+ !(wiphy->features & NL80211_FEATURE_LOW_PRIORITY_SCAN)) ||
+ ((*flags & NL80211_SCAN_FLAG_LOW_SPAN) &&
+ !wiphy_ext_feature_isset(wiphy,
+ NL80211_EXT_FEATURE_LOW_SPAN_SCAN)) ||
+ ((*flags & NL80211_SCAN_FLAG_LOW_POWER) &&
+ !wiphy_ext_feature_isset(wiphy,
+ NL80211_EXT_FEATURE_LOW_POWER_SCAN)) ||
+ ((*flags & NL80211_SCAN_FLAG_HIGH_ACCURACY) &&
+ !wiphy_ext_feature_isset(wiphy,
+ NL80211_EXT_FEATURE_HIGH_ACCURACY_SCAN)))
return -EOPNOTSUPP;
if (*flags & NL80211_SCAN_FLAG_RANDOM_ADDR) {
--
2.19.2