From 4b40571eaf423b96e3809006bd192b4efd52a64b Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Thu, 8 Dec 2016 10:38:08 +0100 Subject: [PATCH] iwlwifi: mvm: align copy-break SKB payload for MQ RX When a small frame is copied completely into the skb->head, the code doesn't take alignment into account, making mac80211 copy it again later on architectures that need the alignment. Avoid this by taking the PAD flag from the device into account when copying. Signed-off-by: Johannes Berg Signed-off-by: Luca Coelho --- drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c b/drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c index 6c802cee900c..c154ab42c80d 100644 --- a/drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c +++ b/drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c @@ -149,8 +149,17 @@ static void iwl_mvm_create_skb(struct sk_buff *skb, struct ieee80211_hdr *hdr, unsigned int headlen, fraglen, pad_len = 0; unsigned int hdrlen = ieee80211_hdrlen(hdr->frame_control); - if (desc->mac_flags2 & IWL_RX_MPDU_MFLG2_PAD) + if (desc->mac_flags2 & IWL_RX_MPDU_MFLG2_PAD) { pad_len = 2; + + /* + * If the device inserted padding it means that (it thought) + * the 802.11 header wasn't a multiple of 4 bytes long. In + * this case, reserve two bytes at the start of the SKB to + * align the payload properly in case we end up copying it. + */ + skb_reserve(skb, pad_len); + } len -= pad_len; /* If frame is small enough to fit in skb->head, pull it completely. -- 2.20.1