Return false from can_receive() when the FIFO doesn't have a free RX slot. This fixes a bug in the current code where the allocated buffer is freed before the fifo pop, triggering a premature flush of queued RX packets. It also will handle a corner case, where the guest manually frees the allocated buffer before popping the rx FIFO (hence it is not enough to just delay the flush_queued_packets()).
Reported-by: Richard Purdie <richard.pur...@linuxfoundation.org> Signed-off-by: Peter Crosthwaite <crosthwaite.pe...@gmail.com> --- hw/net/smc91c111.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/hw/net/smc91c111.c b/hw/net/smc91c111.c index 5774eff..8fc3deb 100644 --- a/hw/net/smc91c111.c +++ b/hw/net/smc91c111.c @@ -129,7 +129,8 @@ static int smc91c111_can_receive(smc91c111_state *s) if ((s->rcr & RCR_RXEN) == 0 || (s->rcr & RCR_SOFT_RST)) { return 1; } - if (s->allocated == (1 << NUM_PACKETS) - 1) { + if (s->allocated == (1 << NUM_PACKETS) - 1 || + s->rx_fifo_len == NUM_PACKETS) { return 0; } return 1; @@ -182,6 +183,7 @@ static void smc91c111_pop_rx_fifo(smc91c111_state *s) } else { s->int_level &= ~INT_RCV; } + smc91c111_flush_queued_packets(s); smc91c111_update(s); } -- 1.9.1