Return-path: Received: from sabertooth01.qualcomm.com ([65.197.215.72]:50773 "EHLO sabertooth01.qualcomm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752345AbbGWXdI (ORCPT ); Thu, 23 Jul 2015 19:33:08 -0400 From: Peter Oh To: CC: Subject: [PATCH] ath10k: initialize msdu ext. descriptor before use Date: Thu, 23 Jul 2015 16:32:06 -0700 Message-ID: <1437694326-31977-1-git-send-email-poh@qca.qualcomm.com> (sfid-20150724_013312_165079_D563CDAC) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-wireless-owner@vger.kernel.org List-ID: Initial QCA99X0 support has a known issue with TCP Tx throughput. All other path such as UDP Tx/Rx and TCP Rx meet their expectation (> 900Mbps), but TCP Tx marked as low as 5Mbps when single pair is used on iperf. The root cause is turned out because TSO flag is not initialized properly so that firmware configures TSO in wrong way. TSO flags in msdu extension descriptor is required to be reset to indicate firmware there is no TSO is enabled, otherwise it could act as TSO is enabled which causes huge throughput drop. In fact, it's enough by resetting TSO flags only to prevent the unexpected behavior, but initializing whole msdu ext. descriptor will help to clear uncertainty of firmware could bring on as it constantly updated. Signed-off-by: Peter Oh --- drivers/net/wireless/ath/ath10k/htt_tx.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/net/wireless/ath/ath10k/htt_tx.c b/drivers/net/wireless/ath/ath10k/htt_tx.c index c49ecff..1c61c17 100644 --- a/drivers/net/wireless/ath/ath10k/htt_tx.c +++ b/drivers/net/wireless/ath/ath10k/htt_tx.c @@ -540,14 +540,14 @@ int ath10k_htt_tx(struct ath10k_htt *htt, struct sk_buff *msdu) /* pass through */ case ATH10K_HW_TXRX_ETHERNET: if (ar->hw_params.continuous_frag_desc) { + memset(&htt->frag_desc.vaddr[msdu_id], 0, + sizeof(struct htt_msdu_ext_desc)); frags = (struct htt_data_tx_desc_frag *) &htt->frag_desc.vaddr[msdu_id].frags; frags[0].tword_addr.paddr_lo = __cpu_to_le32(skb_cb->paddr); frags[0].tword_addr.paddr_hi = 0; frags[0].tword_addr.len_16 = __cpu_to_le16(msdu->len); - frags[1].tword_addr.paddr_lo = 0; - frags[1].tword_addr.paddr_hi = 0; frags_paddr = htt->frag_desc.paddr + (sizeof(struct htt_msdu_ext_desc) * msdu_id); -- 1.9.1