[PATCH AUTOSEL 4.19 164/191] iwlwifi: pcie: gen2: build A-MSDU only for GSO

[Sasha Levin <sashal@kernel.org>]

From: Johannes Berg <johannes.berg@intel.com>

[ Upstream commit 53f474e6a8d74d5dc0c3a015d889471f9a157685 ]

If the incoming frame should be an A-MSDU, it may already be one,
for example in the case of NAN multicast being encapsulated in an
A-MSDU. Thus, use the GSO algorithm to build A-MSDU only if the
skb actually contains GSO data.

Fixes: 6ffe5de35b05 ("iwlwifi: pcie: add AMSDU to gen2")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/wireless/intel/iwlwifi/pcie/tx-gen2.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/tx-gen2.c b/drivers/net/wireless/intel/iwlwifi/pcie/tx-gen2.c
index b99f33ff91230..61ffa1d1a00d7 100644
--- a/drivers/net/wireless/intel/iwlwifi/pcie/tx-gen2.c
+++ b/drivers/net/wireless/intel/iwlwifi/pcie/tx-gen2.c
@@ -526,7 +526,12 @@ struct iwl_tfh_tfd *iwl_pcie_gen2_build_tfd(struct iwl_trans *trans,
 
 	hdr_len = ieee80211_hdrlen(hdr->frame_control);
 
-	if (amsdu)
+	/*
+	 * Only build A-MSDUs here if doing so by GSO, otherwise it may be
+	 * an A-MSDU for other reasons, e.g. NAN or an A-MSDU having been
+	 * built in the higher layers already.
+	 */
+	if (amsdu && skb_shinfo(skb)->gso_size)
 		return iwl_pcie_gen2_build_tx_amsdu(trans, txq, dev_cmd, skb,
 						    out_meta, hdr_len, len);
 
-- 
2.20.1