mac80211: Fix accounting of multicast frames

Since multicast frames are marked as no-ack, using
IEEE80211_TX_STAT_ACK to check if they have been
successfully transmitted by the driver is incorrect
since a driver can choose to ignore transmission status
for no-ack frames. This results in incorrect accounting
for such frames.

To fix this issue, this patch introduces a new flag
that can be used by drivers to indicate error-free
transmission of no-ack frames.

Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
[add a note about not setting the flag for non-no-ack frames]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index b36e60d4c518..b24ef577aed9 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -505,6 +505,11 @@ struct ieee80211_bss_conf {
  * @IEEE80211_TX_CTL_DONTFRAG: Don't fragment this packet even if it
  *      would be fragmented by size (this is optional, only used for
  *      monitor injection).
+ * @IEEE80211_TX_STAT_NOACK_TRANSMITTED: A frame that was marked with
+ *      IEEE80211_TX_CTL_NO_ACK has been successfully transmitted without
+ *      any errors (like issues specific to the driver/HW).
+ *      This flag must not be set for frames that don't request no-ack
+ *      behaviour with IEEE80211_TX_CTL_NO_ACK.
  *
  * Note: If you have to add new flags to the enumeration, then don't
  *       forget to update %IEEE80211_TX_TEMPORARY_FLAGS when necessary.
@@ -540,6 +545,7 @@ enum mac80211_tx_info_flags {
         IEEE80211_TX_STATUS_EOSP                = BIT(28),
         IEEE80211_TX_CTL_USE_MINRATE            = BIT(29),
         IEEE80211_TX_CTL_DONTFRAG               = BIT(30),
+        IEEE80211_TX_STAT_NOACK_TRANSMITTED     = BIT(31),
 };
 
 #define IEEE80211_TX_CTL_STBC_SHIFT             23