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| author | Emmanuel Grumbach <emmanuel.grumbach@intel.com> | 2018-04-08 12:33:31 +0300 |
|---|---|---|
| committer | Luca Coelho <luciano.coelho@intel.com> | 2018-05-30 09:33:36 +0300 |
| commit | 0eac9abace1629c20420d9122d6edc80d292b0ec (patch) | |
| tree | deab89789db2dd9958a55fd2655f0882089c8732 | |
| parent | 15c4e33030d172ac0d2a03ebbae4c3687a80ac7d (diff) | |
| download | nfc-next-0eac9abace1629c20420d9122d6edc80d292b0ec.tar.gz | |
iwlwifi: mvm: fix TSO with highly fragmented SKBs
Our hardware has a limited amount of buffer descriptors
for each Tx packet. Because of that, there is a short
piece of code that makes sure that that we don't push too
many subframes in an A-MSDU because of subframes needs 2
buffer descriptors. This code also takes into account the
number of fragment of the skb since we also need a buffer
descriptor for each fragment in the skb.
This piece of code though didn't check that the resulting
number of subframes wasn't 0.
A user reported that using NFS client, he could get skbs
that are so fragmented that the code mentioned above
returned 0 for the number of subframes making
skb_gso_segment fail and subconsequently iwlwifi would WARN.
Fix this by make sure that num_subframes is at least 1.
This fixes:
https://bugzilla.kernel.org/show_bug.cgi?id=199209
Fixes: a6d5e32f247c ("iwlwifi: mvm: send large SKBs to the transport")
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
| -rw-r--r-- | drivers/net/wireless/intel/iwlwifi/mvm/tx.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/tx.c b/drivers/net/wireless/intel/iwlwifi/mvm/tx.c index df4c60496f72f..0b7f98d002985 100644 --- a/drivers/net/wireless/intel/iwlwifi/mvm/tx.c +++ b/drivers/net/wireless/intel/iwlwifi/mvm/tx.c @@ -843,8 +843,6 @@ static int iwl_mvm_tx_tso(struct iwl_mvm *mvm, struct sk_buff *skb, * N * subf_len + (N - 1) * pad. */ num_subframes = (max_amsdu_len + pad) / (subf_len + pad); - if (num_subframes > 1) - *ieee80211_get_qos_ctl(hdr) |= IEEE80211_QOS_CTL_A_MSDU_PRESENT; tcp_payload_len = skb_tail_pointer(skb) - skb_transport_header(skb) - tcp_hdrlen(skb) + skb->data_len; @@ -855,10 +853,12 @@ static int iwl_mvm_tx_tso(struct iwl_mvm *mvm, struct sk_buff *skb, * 1 more for each fragment * 1 more for the potential data in the header */ - num_subframes = - min_t(unsigned int, num_subframes, - (mvm->trans->max_skb_frags - 1 - - skb_shinfo(skb)->nr_frags) / 2); + if ((num_subframes * 2 + skb_shinfo(skb)->nr_frags + 1) > + mvm->trans->max_skb_frags) + num_subframes = 1; + + if (num_subframes > 1) + *ieee80211_get_qos_ctl(hdr) |= IEEE80211_QOS_CTL_A_MSDU_PRESENT; /* This skb fits in one single A-MSDU */ if (num_subframes * mss >= tcp_payload_len) { |