Return-path: Received: from mail-qa0-f49.google.com ([209.85.216.49]:32958 "EHLO mail-qa0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751355AbaIJBLW (ORCPT ); Tue, 9 Sep 2014 21:11:22 -0400 Received: by mail-qa0-f49.google.com with SMTP id i13so1736660qae.36 for ; Tue, 09 Sep 2014 18:11:21 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: References: <1410268021-9529-1-git-send-email-emmanuel.grumbach@intel.com> From: Julian Calaby Date: Wed, 10 Sep 2014 11:11:01 +1000 Message-ID: (sfid-20140910_031126_641789_9CE8F99F) Subject: Re: [PATCH] cfg802111/nl80211: Add device motion indication API To: Henning Rogge Cc: Emmanuel Grumbach , "linux-wireless@vger.kernel.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-wireless-owner@vger.kernel.org List-ID: Hi Henning, On Wed, Sep 10, 2014 at 1:45 AM, Henning Rogge wrote: > Hi, > > I am curious, what is the use case for this API? Is there really > 802.11 hardware that tracks its physical motion? I was thinking this might be useful for something like a combined WiFi + Bluetooth + cellular + GPS chipset in a tablet or laptop. Thanks, Julian Calaby > Henning Rogge > > On Tue, Sep 9, 2014 at 3:07 PM, Emmanuel Grumbach > wrote: >> From: Avraham Stern >> >> Add API to notify user-space when the device is in motion >> and the motion type. >> This information can be used to react to the changing environment when >> the device is on the move, or avoid some unnecessary activities when >> the device is not moving. For example, longer scan intervals when the >> device is not moving and there are probably no new AP's, shorter scan >> intervals while the device is moving slowly and the environment is >> constantly changing, and not scanning at all when the device is moving >> fast and it is very unlikely to be able to connect to anything. >> >> Signed-off-by: Avraham Stern >> Signed-off-by: Emmanuel Grumbach >> --- >> include/net/cfg80211.h | 14 ++++++++ >> include/uapi/linux/nl80211.h | 39 ++++++++++++++++++++++ >> net/wireless/core.h | 2 ++ >> net/wireless/nl80211.c | 78 ++++++++++++++++++++++++++++++++++++++++++++ >> net/wireless/trace.h | 14 ++++++++ >> 5 files changed, 147 insertions(+) >> >> diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h >> index b960c4d..6210822 100644 >> --- a/include/net/cfg80211.h >> +++ b/include/net/cfg80211.h >> @@ -4914,6 +4914,20 @@ void cfg80211_shutdown_all_interfaces(struct wiphy *wiphy); >> /* ethtool helper */ >> void cfg80211_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info); >> >> +/* >> + * cfg80211_device_motion_notify - notify device motion type >> + * >> + * @wiphy: the wiphy >> + * @type: the motion type as specified in &enum nl80211_device_motion_type. >> + * @gfp: allocation flags >> + * >> + * This function is used to report to userspace the type of motion the device >> + * is currently in. >> + */ >> +void cfg80211_device_motion_notify(struct wiphy *wiphy, >> + enum nl80211_device_motion_type type, >> + gfp_t gfp); >> + >> /* Logging, debugging and troubleshooting/diagnostic helpers. */ >> >> /* wiphy_printk helpers, similar to dev_printk */ >> diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h >> index 8270024..fae01c7 100644 >> --- a/include/uapi/linux/nl80211.h >> +++ b/include/uapi/linux/nl80211.h >> @@ -733,6 +733,19 @@ >> * QoS mapping is relevant for IP packets, it is only valid during an >> * association. This is cleared on disassociation and AP restart. >> * >> + * @NL80211_CMD_DEVICE_MOTION_NOTIFY: Device motion notification. This command >> + * is used as an event to indicate the motion type the device is currently >> + * in. This command can also be used by userspace to get the current >> + * motion type. The motion type is specified by the >> + * %NL80211_ATTR_DEVICE_MOTION_TYPE. This information can be used to react >> + * to the changing environment when the device is on the move, or avoid >> + * some unnecessary activities when the device is not moving. For example, >> + * longer scan intervals when the device is not moving and neighbor AP's >> + * probably stay the same, shorter scan intervals while the device is >> + * moving slowly and the environment is changing constantly, and not >> + * scanning at all when the device is moving fast and it is very unlikely >> + * to be able to connect to anything. >> + * >> * @NL80211_CMD_MAX: highest used command number >> * @__NL80211_CMD_AFTER_LAST: internal use >> */ >> @@ -906,6 +919,8 @@ enum nl80211_commands { >> >> NL80211_CMD_CH_SWITCH_STARTED_NOTIFY, >> >> + NL80211_CMD_DEVICE_MOTION_NOTIFY, >> + >> /* add new commands above here */ >> >> /* used to define NL80211_CMD_MAX below */ >> @@ -1620,6 +1635,9 @@ enum nl80211_commands { >> * association request. In addition, it must also set the RRM capability >> * flag in the association request's Capability Info field. >> * >> + * @NL80211_ATTR_DEVICE_MOTION_TYPE: The type of motion the device is currently >> + * in. As specified in &enum nl80211_device_motion_type. >> + * >> * @NL80211_ATTR_MAX: highest attribute number currently defined >> * @__NL80211_ATTR_AFTER_LAST: internal use >> */ >> @@ -1964,6 +1982,8 @@ enum nl80211_attrs { >> >> NL80211_ATTR_USE_RRM, >> >> + NL80211_ATTR_DEVICE_MOTION_TYPE, >> + >> /* add attributes here, update the policy in nl80211.c */ >> >> __NL80211_ATTR_AFTER_LAST, >> @@ -4223,4 +4243,23 @@ enum nl80211_tdls_peer_capability { >> NL80211_TDLS_PEER_WMM = 1<<2, >> }; >> >> +/** >> + * enum nl80211_device_motion_type - device motion types >> + * @NL80211_DEVICE_MOTION_TYPE_UNKNOWN: The device motion type is not known >> + * or has not been set yet. >> + * @NL80211_DEVICE_MOTION_TYPE_NOT_MOVING: The device is not moving. This >> + * includes cases in which the device is moving but its immediate >> + * environment is moving as well, e.g. while on board a train. >> + * @NL80211_DEVICE_MOTION_TYPE_MOVING_SLOWLY: The device is moving slowly enough >> + * to keep track of the changing environment. >> + * @NL80211_DEVICE_MOTION_TYPE_MOVING_FAST: The device is moving fast which >> + * makes it hard to keep track of the changing environment. >> + */ >> +enum nl80211_device_motion_type { >> + NL80211_DEVICE_MOTION_TYPE_UNKNOWN, >> + NL80211_DEVICE_MOTION_TYPE_NOT_MOVING, >> + NL80211_DEVICE_MOTION_TYPE_MOVING_SLOWLY, >> + NL80211_DEVICE_MOTION_TYPE_MOVING_FAST, >> +}; >> + >> #endif /* __LINUX_NL80211_H */ >> diff --git a/net/wireless/core.h b/net/wireless/core.h >> index 21d4b1d..a00be85 100644 >> --- a/net/wireless/core.h >> +++ b/net/wireless/core.h >> @@ -84,6 +84,8 @@ struct cfg80211_registered_device { >> struct list_head destroy_list; >> struct work_struct destroy_work; >> >> + enum nl80211_device_motion_type motion_type; >> + >> /* must be last because of the way we do wiphy_priv(), >> * and it should at least be aligned to NETDEV_ALIGN */ >> struct wiphy wiphy __aligned(NETDEV_ALIGN); >> diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c >> index 03b5b5e..c7c014c 100644 >> --- a/net/wireless/nl80211.c >> +++ b/net/wireless/nl80211.c >> @@ -9451,6 +9451,48 @@ static int nl80211_set_qos_map(struct sk_buff *skb, >> return ret; >> } >> >> +static int nl80211_send_motion(struct sk_buff *msg, u32 portid, u32 seq, >> + int flags, >> + struct cfg80211_registered_device *rdev) >> +{ >> + void *hdr; >> + >> + hdr = nl80211hdr_put(msg, portid, seq, flags, >> + NL80211_CMD_DEVICE_MOTION_NOTIFY); >> + if (!hdr) >> + return -ENOBUFS; >> + >> + if (nla_put_u32(msg, NL80211_ATTR_WIPHY, rdev->wiphy_idx) || >> + nla_put_u32(msg, NL80211_ATTR_DEVICE_MOTION_TYPE, >> + rdev->motion_type)) >> + goto nla_put_failure; >> + >> + return genlmsg_end(msg, hdr); >> + >> + nla_put_failure: >> + genlmsg_cancel(msg, hdr); >> + return -ENOBUFS; >> +} >> + >> +static int nl80211_device_motion_notify(struct sk_buff *skb, >> + struct genl_info *info) >> +{ >> + struct sk_buff *msg; >> + struct cfg80211_registered_device *rdev = info->user_ptr[0]; >> + >> + msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); >> + if (!msg) >> + return -ENOMEM; >> + >> + if (nl80211_send_motion(msg, genl_info_snd_portid(info), info->snd_seq, >> + 0, rdev) < 0) { >> + nlmsg_free(msg); >> + return -ENOBUFS; >> + } >> + >> + return genlmsg_reply(msg, info); >> +} >> + >> #define NL80211_FLAG_NEED_WIPHY 0x01 >> #define NL80211_FLAG_NEED_NETDEV 0x02 >> #define NL80211_FLAG_NEED_RTNL 0x04 >> @@ -10197,6 +10239,14 @@ static __genl_const struct genl_ops nl80211_ops[] = { >> .internal_flags = NL80211_FLAG_NEED_NETDEV_UP | >> NL80211_FLAG_NEED_RTNL, >> }, >> + { >> + .cmd = NL80211_CMD_DEVICE_MOTION_NOTIFY, >> + .doit = nl80211_device_motion_notify, >> + .policy = nl80211_policy, >> + .flags = GENL_ADMIN_PERM, >> + .internal_flags = NL80211_FLAG_NEED_WIPHY | >> + NL80211_FLAG_NEED_RTNL, >> + }, >> }; >> >> /* notification functions */ >> @@ -12004,6 +12054,34 @@ void cfg80211_crit_proto_stopped(struct wireless_dev *wdev, gfp_t gfp) >> } >> EXPORT_SYMBOL(cfg80211_crit_proto_stopped); >> >> +void cfg80211_device_motion_notify(struct wiphy *wiphy, >> + enum nl80211_device_motion_type type, >> + gfp_t gfp) >> +{ >> + struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy); >> + struct sk_buff *msg; >> + >> + trace_cfg80211_device_motion_notify(wiphy, type); >> + >> + if (rdev->motion_type == type) >> + return; >> + >> + rdev->motion_type = type; >> + >> + msg = nlmsg_new(NLMSG_DEFAULT_SIZE, gfp); >> + if (!msg) >> + return; >> + >> + if (nl80211_send_motion(msg, 0, 0, 0, rdev) < 0) { >> + nlmsg_free(msg); >> + return; >> + } >> + >> + genlmsg_multicast_netns(&nl80211_fam, wiphy_net(wiphy), msg, 0, >> + NL80211_MCGRP_SCAN, gfp); >> +} >> +EXPORT_SYMBOL(cfg80211_device_motion_notify); >> + >> void nl80211_send_ap_stopped(struct wireless_dev *wdev) >> { >> struct wiphy *wiphy = wdev->wiphy; >> diff --git a/net/wireless/trace.h b/net/wireless/trace.h >> index 0f0901e..e39a950 100644 >> --- a/net/wireless/trace.h >> +++ b/net/wireless/trace.h >> @@ -2627,6 +2627,20 @@ TRACE_EVENT(cfg80211_stop_iface, >> WIPHY_PR_ARG, WDEV_PR_ARG) >> ); >> >> +TRACE_EVENT(cfg80211_device_motion_notify, >> + TP_PROTO(struct wiphy *wiphy, enum nl80211_device_motion_type type), >> + TP_ARGS(wiphy, type), >> + TP_STRUCT__entry( >> + WIPHY_ENTRY >> + __field(enum nl80211_device_motion_type, type) >> + ), >> + TP_fast_assign( >> + WIPHY_ASSIGN; >> + __entry->type = type; >> + ), >> + TP_printk(WIPHY_PR_FMT ", type: %d", WIPHY_PR_ARG, __entry->type) >> +); >> + >> #endif /* !__RDEV_OPS_TRACE || TRACE_HEADER_MULTI_READ */ >> >> #undef TRACE_INCLUDE_PATH >> -- >> 1.9.1 >> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-wireless" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html > -- > To unsubscribe from this list: send the line "unsubscribe linux-wireless" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Julian Calaby Email: julian.calaby@gmail.com Profile: http://www.google.com/profiles/julian.calaby/