Commit 6cdfab28 authored by Michael S. Tsirkin's avatar Michael S. Tsirkin
Browse files

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: default avatarMichael S. Tsirkin <mst@redhat.com>
parent 89c473fd

hw/e1000.c

+8 −8
Original line number Diff line number Diff line
@@ -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)

{