Messages in this thread Patch in this message | | | Date | Thu, 05 May 2011 17:21:13 -0700 | From | Greg KH <> | Subject | [088/143] mac80211: Add define for TX headroom reserved by mac80211 itself. |
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2.6.32-longterm review patch. If anyone has any objections, please let us know.
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From: Gertjan van Wingerde <gwingerde@gmail.com>
commit d24deb2580823ab0b8425790c6f5d18e2ff749d8 upstream.
Add a definition of the amount of TX headroom reserved by mac80211 itself for its own purposes. Also add BUILD_BUG_ON to validate the value. This define can then be used by drivers to request additional TX headroom in the most efficient manner.
Signed-off-by: Gertjan van Wingerde <gwingerde@gmail.com> Acked-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: John W. Linville <linville@tuxdriver.com> [bwh: Adjust context for 2.6.32] Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> --- include/net/mac80211.h | 6 ++++++ net/mac80211/main.c | 2 ++ 2 files changed, 8 insertions(+)
--- a/include/net/mac80211.h +++ b/include/net/mac80211.h @@ -1700,6 +1700,12 @@ void ieee80211_rx(struct ieee80211_hw *h */ void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb); +/* + * The TX headroom reserved by mac80211 for its own tx_status functions. + * This is enough for the radiotap header. + */ +#define IEEE80211_TX_STATUS_HEADROOM 13 + /** * ieee80211_tx_status - transmit status callback * --- a/net/mac80211/main.c +++ b/net/mac80211/main.c @@ -859,6 +859,8 @@ int ieee80211_register_hw(struct ieee802 * and we need some headroom for passing the frame to monitor * interfaces, but never both at the same time. */ + BUILD_BUG_ON(IEEE80211_TX_STATUS_HEADROOM != + sizeof(struct ieee80211_tx_status_rtap_hdr)); local->tx_headroom = max_t(unsigned int , local->hw.extra_tx_headroom, sizeof(struct ieee80211_tx_status_rtap_hdr));
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