From: Johannes Berg <johannes.berg@xxxxxxxxx> commit 4f4925a7b23428d5719af5a2816586b2a0e6fd19 upstream. When the implementation of SKBs with fraglist was sent upstream, a merge-damage occurred and half the patch was not applied. This causes problems in high-throughput situations with AX200 devices, including low throughput and FW crashes. Introduce the part that was missing from the original patch. Fixes: 0044f1716c4d ("iwlwifi: pcie: support transmitting SKBs with fraglist") Cc: stable@xxxxxxxxxxxxxxx # 4.20+ Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx> [ This patch was created by me, but the original author of this code is Johannes, so his s-o-b is here and he's marked as the author of the patch. ] Signed-off-by: Luca Coelho <luciano.coelho@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/wireless/intel/iwlwifi/pcie/tx-gen2.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) --- a/drivers/net/wireless/intel/iwlwifi/pcie/tx-gen2.c +++ b/drivers/net/wireless/intel/iwlwifi/pcie/tx-gen2.c @@ -468,6 +468,7 @@ iwl_tfh_tfd *iwl_pcie_gen2_build_tx(stru dma_addr_t tb_phys; int len, tb1_len, tb2_len; void *tb1_addr; + struct sk_buff *frag; tb_phys = iwl_pcie_get_first_tb_dma(txq, idx); @@ -516,6 +517,19 @@ iwl_tfh_tfd *iwl_pcie_gen2_build_tx(stru if (iwl_pcie_gen2_tx_add_frags(trans, skb, tfd, out_meta)) goto out_err; + skb_walk_frags(skb, frag) { + tb_phys = dma_map_single(trans->dev, frag->data, + skb_headlen(frag), DMA_TO_DEVICE); + if (unlikely(dma_mapping_error(trans->dev, tb_phys))) + goto out_err; + iwl_pcie_gen2_set_tb(trans, tfd, tb_phys, skb_headlen(frag)); + trace_iwlwifi_dev_tx_tb(trans->dev, skb, + frag->data, + skb_headlen(frag)); + if (iwl_pcie_gen2_tx_add_frags(trans, frag, tfd, out_meta)) + goto out_err; + } + return tfd; out_err: