e1000: check buffer availability

Reduce spurious packet drops on RX ring empty
by verifying that we have at least 1 buffer
ahead of the time.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Michael S. Tsirkin 2011-03-27 13:37:35 +02:00
parent 89c473fd82
commit 6cdfab2868

View File

@ -625,14 +625,6 @@ e1000_set_link_status(VLANClientState *nc)
set_ics(s, 0, E1000_ICR_LSC);
}
static int
e1000_can_receive(VLANClientState *nc)
{
E1000State *s = DO_UPCAST(NICState, nc, nc)->opaque;
return (s->mac_reg[RCTL] & E1000_RCTL_EN);
}
static bool e1000_has_rxbufs(E1000State *s, size_t total_size)
{
int bufs;
@ -651,6 +643,14 @@ static bool e1000_has_rxbufs(E1000State *s, size_t total_size)
return total_size <= bufs * s->rxbuf_size;
}
static int
e1000_can_receive(VLANClientState *nc)
{
E1000State *s = DO_UPCAST(NICState, nc, nc)->opaque;
return (s->mac_reg[RCTL] & E1000_RCTL_EN) && e1000_has_rxbufs(s, 1);
}
static ssize_t
e1000_receive(VLANClientState *nc, const uint8_t *buf, size_t size)
{