Return false from can_recieve() when no valid buffer descriptor is
available. Ensures against mass packet droppage in some applications.
Signed-off-by: Peter Crosthwaite <peter.crosthwa...@xilinx.com>
---
hw/net/cadence_gem.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/hw/net/cadence_gem.c b/hw/net/cadence_gem.c
index 8c2d8fc..a0499ac 100644
--- a/hw/net/cadence_gem.c
+++ b/hw/net/cadence_gem.c
@@ -463,6 +463,15 @@ static int gem_can_receive(NetClientState *nc)
return 0;
}
+ if (rx_desc_get_ownership(s->rx_desc) == 1) {
+ if (s->can_rx_state != 2) {
+ s->can_rx_state = 2;
+ DB_PRINT("cant receive - busy buffer descriptor 0x%x\n",
+ s->rx_desc_addr);
+ }
+ return 0;
+ }
+
if (s->can_rx_state != 0) {
s->can_rx_state = 0;
DB_PRINT("can receive 0x%x\n", s->rx_desc_addr);
@@ -1144,7 +1153,7 @@ static void gem_write(void *opaque, hwaddr offset,
uint64_t val,
/* Reset to start of Q when transmit disabled. */
s->tx_desc_addr = s->regs[GEM_TXQBASE];
}
- if (val & GEM_NWCTRL_RXENA) {
+ if (gem_can_receive(qemu_get_queue(s->nic))) {
qemu_flush_queued_packets(qemu_get_queue(s->nic));
}
break;
--
1.8.4.4
