From c9d534c8cbaedbb522a1d2cb037c6c394f610317 Mon Sep 17 00:00:00 2001 From: Jon Mason Date: Fri, 1 Feb 2013 15:45:16 -0700 Subject: [PATCH] NTB: Correctly handle receive buffers of the minimal size 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 73a000ed7a9f..cd9745b062e4 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) { -- GitLab