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 <jon.mason@intel.com>
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 @@
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 @@
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) {