Add missing bus_dmamap_sync() calls. If you are using an architecture

with a weak memory model or x86 + PAE (or more specifically, your
driver is using bounce pages) and you have had problems with em(4),
this may fix it.  At least this is needed to have em(4) work properly
on FreeBSD/arm.

Original version by:	cognet
Reviewed by:		tackerman
Tested by:		cognet

1 files changed, 12 insertions, 2 deletions

diff --git a/sys/dev/em/if_em.c b/sys/dev/em/if_em.c
index a90eb7a..4c896bf 100644
--- a/sys/dev/em/if_em.c
+++ b/sys/dev/em/if_em.c
@@ -1339,6 +1339,8 @@ em_encap(struct adapter *adapter, struct mbuf *m_head)
          * Advance the Transmit Descriptor Tail (Tdt), this tells the E1000
          * that this frame is available to transmit.
          */
+        bus_dmamap_sync(adapter->txdma.dma_tag, adapter->txdma.dma_map,
+            BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
         if (adapter->hw.mac_type == em_82547 &&
             adapter->link_duplex == HALF_DUPLEX) {
                 em_82547_move_tail_locked(adapter);
@@ -2390,6 +2392,8 @@ em_clean_transmit_interrupts(struct adapter * adapter)
         tx_buffer = &adapter->tx_buffer_area[i];
         tx_desc = &adapter->tx_desc_base[i];
 
+        bus_dmamap_sync(adapter->txdma.dma_tag, adapter->txdma.dma_map,
+            BUS_DMASYNC_POSTREAD);
         while (tx_desc->upper.fields.status & E1000_TXD_STAT_DD) {
 
                 tx_desc->upper.data = 0;
@@ -2397,8 +2401,6 @@ em_clean_transmit_interrupts(struct adapter * adapter)
 
                 if (tx_buffer->m_head) {
 			ifp->if_opackets++;
-                        bus_dmamap_sync(adapter->txtag, tx_buffer->map,
-                                        BUS_DMASYNC_POSTWRITE);
                         bus_dmamap_unload(adapter->txtag, tx_buffer->map);
                         bus_dmamap_destroy(adapter->txtag, tx_buffer->map);
 
@@ -2412,6 +2414,8 @@ em_clean_transmit_interrupts(struct adapter * adapter)
                 tx_buffer = &adapter->tx_buffer_area[i];
                 tx_desc = &adapter->tx_desc_base[i];
         }
+        bus_dmamap_sync(adapter->txdma.dma_tag, adapter->txdma.dma_map,
+            BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
 
         adapter->oldest_used_tx_desc = i;
 
@@ -2551,6 +2555,8 @@ em_allocate_receive_structures(struct adapter * adapter)
                         return(error);
                 }
         }
+        bus_dmamap_sync(adapter->rxdma.dma_tag, adapter->rxdma.dma_map,
+            BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
 
         return(0);
 
@@ -2736,6 +2742,8 @@ em_process_receive_interrupts(struct adapter * adapter, int count)
 	ifp = &adapter->interface_data.ac_if;
 	i = adapter->next_rx_desc_to_check;
         current_desc = &adapter->rx_desc_base[i];
+	bus_dmamap_sync(adapter->rxdma.dma_tag, adapter->rxdma.dma_map,
+	    BUS_DMASYNC_POSTREAD);
 
 	if (!((current_desc->status) & E1000_RXD_STAT_DD)) {
 #ifdef DBG_STATS
@@ -2883,6 +2891,8 @@ em_process_receive_interrupts(struct adapter * adapter, int count)
                 } else
 			current_desc++;
 	}
+	bus_dmamap_sync(adapter->rxdma.dma_tag, adapter->rxdma.dma_map,
+	    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
 	adapter->next_rx_desc_to_check = i;
 	return;
 }