Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752734Ab3EROsj (ORCPT ); Sat, 18 May 2013 10:48:39 -0400 Received: from mga03.intel.com ([143.182.124.21]:47439 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752537Ab3EROsh (ORCPT ); Sat, 18 May 2013 10:48:37 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.87,700,1363158000"; d="scan'208";a="243460022" Date: Sat, 18 May 2013 07:48:36 -0700 From: Jon Mason To: Jonghwan Choi Cc: stable@vger.kernel.org, linux-kernel@vger.kernel.org, Jonghwan Choi Subject: Re: [PATCH 3.9-table] NTB: Correctly handle receive buffers of the minimal size Message-ID: <20130518144836.GE29066@jonmason-lab> References: <1368845379-4177-1-git-send-email-jhbird.choi@samsung.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1368845379-4177-1-git-send-email-jhbird.choi@samsung.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2617 Lines: 68 On Sat, May 18, 2013 at 11:49:39AM +0900, Jonghwan Choi wrote: > From: Jon Mason > > This patch looks like it should be in the 3.9-stable tree, should we apply > it? Yes, thanks. > > ------------------ > > 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/