Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757621Ab3EVWMS (ORCPT ); Wed, 22 May 2013 18:12:18 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:42162 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757538Ab3EVWKw (ORCPT ); Wed, 22 May 2013 18:10:52 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jon Mason Subject: [ 17/21] NTB: Correctly handle receive buffers of the minimal size Date: Wed, 22 May 2013 15:10:35 -0700 Message-Id: <20130522205234.618268643@linuxfoundation.org> X-Mailer: git-send-email 1.8.3.rc0.20.gb99dd2e In-Reply-To: <20130522205232.597066680@linuxfoundation.org> References: <20130522205232.597066680@linuxfoundation.org> User-Agent: quilt/0.60-5.1.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1886 Lines: 54 3.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jon Mason commit c9d534c8cbaedbb522a1d2cb037c6c394f610317 upstream. 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 Signed-off-by: Greg Kroah-Hartman --- drivers/ntb/ntb_transport.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) --- a/drivers/ntb/ntb_transport.c +++ b/drivers/ntb/ntb_transport.c @@ -490,11 +490,12 @@ static void ntb_transport_setup_qp_mw(st 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(str 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) { -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/