pcnet: Drop pcnet_can_receive

pcnet_receive already checks the conditions and drop packets if false.
Due to the new semantics since 6e99c63 ("net/socket: Drop
net_socket_can_send"), having .can_receive returning 0 requires us to
explicitly flush the queued packets when the conditions are becoming
true, but queuing the packets when guest driver is not ready doesn't
make much sense.

Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Jason Wang <jasowang@redhat.com>
Message-id: 1436955553-22791-3-git-send-email-famz@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

hw/net/lance.c

@@ -94,7 +94,6 @@ static const MemoryRegionOps lance_mem_ops = {
 static NetClientInfo net_lance_info = {
     .type = NET_CLIENT_OPTIONS_KIND_NIC,
     .size = sizeof(NICState),
-    .can_receive = pcnet_can_receive,
     .receive = pcnet_receive,
     .link_status_changed = pcnet_set_link_status,
 };

hw/net/pcnet-pci.c

@@ -273,7 +273,6 @@ static void pci_pcnet_uninit(PCIDevice *dev)
 static NetClientInfo net_pci_pcnet_info = {
     .type = NET_CLIENT_OPTIONS_KIND_NIC,
     .size = sizeof(NICState),
-    .can_receive = pcnet_can_receive,
     .receive = pcnet_receive,
     .link_status_changed = pcnet_set_link_status,
 };

hw/net/pcnet.c

@@ -995,15 +995,6 @@ static int pcnet_tdte_poll(PCNetState *s)
     return !!(CSR_CXST(s) & 0x8000);
 }
 
-int pcnet_can_receive(NetClientState *nc)
-{
-    PCNetState *s = qemu_get_nic_opaque(nc);
-    if (CSR_STOP(s) || CSR_SPND(s))
-        return 0;
-
-    return sizeof(s->buffer)-16;
-}
-
 #define MIN_BUF_SIZE 60
 
 ssize_t pcnet_receive(NetClientState *nc, const uint8_t *buf, size_t size_)

hw/net/pcnet.h

@@ -60,7 +60,6 @@ uint32_t pcnet_ioport_readw(void *opaque, uint32_t addr);
 void pcnet_ioport_writel(void *opaque, uint32_t addr, uint32_t val);
 uint32_t pcnet_ioport_readl(void *opaque, uint32_t addr);
 uint32_t pcnet_bcr_readw(PCNetState *s, uint32_t rap);
-int pcnet_can_receive(NetClientState *nc);
 ssize_t pcnet_receive(NetClientState *nc, const uint8_t *buf, size_t size_);
 void pcnet_set_link_status(NetClientState *nc);
 void pcnet_common_init(DeviceState *dev, PCNetState *s, NetClientInfo *info);