ps3: fix rare issue that reenabling rx DMA fails

Fixed rare issue that 'lv1_net_start_rx_dma failed, status=-9" was shown
in dmesg.  This meant restarting rx DMA had been rejected by the hypervisor.
This issue would caused if the guest os requested starting DMA when
the hypervisor thought the DMA was in progress.
The state machine for DMA status of the hypervisor would be updated
by processing interrupt in the hypervisor.
Thus we should wait for the interrupt delivery before restarting
DMA.

Signed-off-by: Masakazu Mokuno <mokuno@sm.sony.co.jp>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

drivers/net/ps3_gelic_net.c

@@ -943,8 +943,8 @@ refill:
 	descr->prev->next_descr_addr = descr->bus_addr;
 
 	if (dmac_chain_ended) {
-		gelic_net_enable_rxdmac(card);
-		dev_dbg(ctodev(card), "reenable rx dma\n");
+		card->rx_dma_restart_required = 1;
+		dev_dbg(ctodev(card), "reenable rx dma scheduled\n");
 	}
 
 	return 1;
@@ -1020,6 +1020,11 @@ static irqreturn_t gelic_net_interrupt(int irq, void *ptr)
 	if (!status)
 		return IRQ_NONE;
 
+	if (card->rx_dma_restart_required) {
+		card->rx_dma_restart_required = 0;
+		gelic_net_enable_rxdmac(card);
+	}
+
 	if (status & GELIC_NET_RXINT) {
 		gelic_net_rx_irq_off(card);
 		netif_rx_schedule(netdev);

drivers/net/ps3_gelic_net.h

@@ -206,6 +206,7 @@ struct gelic_net_card {
 
 	struct gelic_net_descr_chain tx_chain;
 	struct gelic_net_descr_chain rx_chain;
+	int rx_dma_restart_required;
 	/* gurad dmac descriptor chain*/
 	spinlock_t chain_lock;