From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759712Ab3EGB5d (ORCPT ); Mon, 6 May 2013 21:57:33 -0400 Received: from mga14.intel.com ([143.182.124.37]:20011 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933006Ab3EGB4E (ORCPT ); Mon, 6 May 2013 21:56:04 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.87,624,1363158000"; d="scan'208";a="329960360" From: Jon Mason To: linux-kernel@vger.kernel.org Cc: Dave Jiang Subject: [PATCH 07/10] NTB: Correctly handle receive buffers of the minimal size Date: Mon, 6 May 2013 18:55:26 -0700 Message-Id: <1367891729-11738-8-git-send-email-jon.mason@intel.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1367891729-11738-1-git-send-email-jon.mason@intel.com> References: <1367891729-11738-1-git-send-email-jon.mason@intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The ring logic of the NTB receive buffer/transmit memory window requires there to be at least 2 payload sized allotments. For the minimal size case, split the buffer into two and set the transport_mtu to the appropriate size. Signed-off-by: Jon Mason --- drivers/ntb/ntb_transport.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c index 73a000e..cd9745b 100644 --- a/drivers/ntb/ntb_transport.c +++ b/drivers/ntb/ntb_transport.c @@ -490,11 +490,12 @@ static void ntb_transport_setup_qp_mw(struct ntb_transport *nt, rx_size -= sizeof(struct ntb_rx_info); qp->rx_buff = qp->remote_rx_info + 1; - qp->rx_max_frame = min(transport_mtu, rx_size); + /* Due to housekeeping, there must be atleast 2 buffs */ + qp->rx_max_frame = min(transport_mtu, rx_size / 2); qp->rx_max_entry = rx_size / qp->rx_max_frame; qp->rx_index = 0; - qp->remote_rx_info->entry = qp->rx_max_entry; + qp->remote_rx_info->entry = qp->rx_max_entry - 1; /* setup the hdr offsets with 0's */ for (i = 0; i < qp->rx_max_entry; i++) { @@ -818,7 +819,8 @@ static void ntb_transport_init_queue(struct ntb_transport *nt, tx_size -= sizeof(struct ntb_rx_info); qp->tx_mw = qp->rx_info + 1; - qp->tx_max_frame = min(transport_mtu, tx_size); + /* Due to housekeeping, there must be atleast 2 buffs */ + qp->tx_max_frame = min(transport_mtu, tx_size / 2); qp->tx_max_entry = tx_size / qp->tx_max_frame; if (nt->debugfs_dir) { -- 1.7.9.5