[3.5.y.z,extended,stable] Patch "iwlwifi: fix monitor mode FCS flag" has been added to staging queue

Message ID 1355149088-7766-1-git-send-email-herton.krzesinski@canonical.com
State New
Headers show

Commit Message

Herton Ronaldo Krzesinski Dec. 10, 2012, 2:18 p.m.
This is a note to let you know that I have just added a patch titled

    iwlwifi: fix monitor mode FCS flag

to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree 
which can be found at:


If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.5.y.z tree, see



From 14845d29bed8d17aa84cefaca00bcc87bf1edeb3 Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg@intel.com>
Date: Tue, 13 Nov 2012 21:28:44 +0100
Subject: [PATCH] iwlwifi: fix monitor mode FCS flag

commit 04baaa27b43d389879237b32f8bd194a94cf1ca7 upstream.

When the firmware is in SNIFFER mode, it leaves
the FCS at the end of frame. Not telling mac80211
means it won't add the right flag to the radiotap
header and that confuses wireshark.

Since mac80211 doesn't have a per-packet flag, set
the HW flag dynamically. This works as the monitor
vif can only be present in the driver by itself.

This fixes a regression introduced by my

commit 578977264199de9815ace51ade87cec4894cf010
Author: Johannes Berg <johannes.berg@intel.com>
Date:   Fri May 11 10:53:18 2012 +0200

    iwlwifi: support explicit monitor interface

Reported-by: MARK PHILLIPS <mark.phillips@virgin.net>
Reviewed-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
[ herton: adjust file name to be patched ]
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com>
 drivers/net/wireless/iwlwifi/iwl-mac80211.c |   14 ++++++++++++++
 1 file changed, 14 insertions(+)



diff --git a/drivers/net/wireless/iwlwifi/iwl-mac80211.c b/drivers/net/wireless/iwlwifi/iwl-mac80211.c
index 0136803..a0b0b78 100644
--- a/drivers/net/wireless/iwlwifi/iwl-mac80211.c
+++ b/drivers/net/wireless/iwlwifi/iwl-mac80211.c
@@ -1343,6 +1343,20 @@  static int iwlagn_mac_add_interface(struct ieee80211_hw *hw,
 	vif_priv->ctx = ctx;
 	ctx->vif = vif;

+	/*
+	 * In SNIFFER device type, the firmware reports the FCS to
+	 * the host, rather than snipping it off. Unfortunately,
+	 * mac80211 doesn't (yet) provide a per-packet flag for
+	 * this, so that we have to set the hardware flag based
+	 * on the interfaces added. As the monitor interface can
+	 * only be present by itself, and will be removed before
+	 * other interfaces are added, this is safe.
+	 */
+	if (vif->type == NL80211_IFTYPE_MONITOR)
+		priv->hw->flags |= IEEE80211_HW_RX_INCLUDES_FCS;
+	else
+		priv->hw->flags &= ~IEEE80211_HW_RX_INCLUDES_FCS;
 	err = iwl_setup_interface(priv, ctx);
 	if (!err || reset)
 		goto out;