Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758501Ab3ERCvv (ORCPT ); Fri, 17 May 2013 22:51:51 -0400 Received: from mail-pb0-f51.google.com ([209.85.160.51]:49318 "EHLO mail-pb0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757346Ab3ERCvu (ORCPT ); Fri, 17 May 2013 22:51:50 -0400 From: Jonghwan Choi To: Jon Mason Cc: stable@vger.kernel.org, linux-kernel@vger.kernel.org, Jonghwan Choi Subject: [PATCH 3.9-table] NTB: Correctly handle receive buffers of the minimal size Date: Sat, 18 May 2013 11:49:39 +0900 Message-Id: <1368845379-4177-1-git-send-email-jhbird.choi@samsung.com> X-Mailer: git-send-email 1.8.1.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2421 Lines: 64 From: Jon Mason This patch looks like it should be in the 3.9-stable tree, should we apply it? ------------------ 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. Cc: # 3.9.x: ad3e2751: ntb: off by one Cc: # 3.9.x: cc0f868d: NTB: fix pointer math Cc: # 3.9.x: 113fc505: NTB: Handle 64bit BAR Cc: # 3.9.x: b77b2637: NTB: Link toggle memory Cc: # 3.9.x: 90f9e934: NTB: reset tx_index on Signed-off-by: Jon Mason Signed-off-by: Jonghwan Choi --- 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 0828124..a288a26 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) { -- 1.8.1.2 -- 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/