D8282.id.diff
No OneTemporary
Actions

Size

1 KB

Referenced Files

None

Subscribers

None

D8282.id.diff
View Options

	Index: head/sys/dev/e1000/if_lem.c
	===================================================================
	--- head/sys/dev/e1000/if_lem.c
	+++ head/sys/dev/e1000/if_lem.c
	@@ -543,8 +543,16 @@
	*/
	adapter->hw.mac.report_tx_early = 1;

	- tsize = roundup2(adapter->num_tx_desc * sizeof(struct e1000_tx_desc),
	- EM_DBA_ALIGN);
	+ /*
	+ * It seems that the descriptor DMA engine on some PCI cards
	+ * fetches memory past the end of the last descriptor in the
	+ * ring. These reads are problematic when VT-d (DMAR) busdma
	+ * is used. Allocate the scratch space to avoid getting
	+ * faults from DMAR, by requesting scratch memory for one more
	+ * descriptor.
	+ */
	+ tsize = roundup2((adapter->num_tx_desc + 1) *
	+ sizeof(struct e1000_tx_desc), EM_DBA_ALIGN);

	/* Allocate Transmit Descriptor ring */
	if (lem_dma_malloc(adapter, tsize, &adapter->txdma, BUS_DMA_NOWAIT)) {
	@@ -555,8 +563,11 @@
	adapter->tx_desc_base =
	(struct e1000_tx_desc *)adapter->txdma.dma_vaddr;

	- rsize = roundup2(adapter->num_rx_desc * sizeof(struct e1000_rx_desc),
	- EM_DBA_ALIGN);
	+ /*
	+ * See comment above txdma allocation for rationale behind +1.
	+ */
	+ rsize = roundup2((adapter->num_rx_desc + 1) *
	+ sizeof(struct e1000_rx_desc), EM_DBA_ALIGN);

	/* Allocate Receive Descriptor ring */
	if (lem_dma_malloc(adapter, rsize, &adapter->rxdma, BUS_DMA_NOWAIT)) {