diff mbox series

[S23,v2,08/15] ice: allow empty rx descriptors

Message ID 20190628150332.59155-8-anthony.l.nguyen@intel.com
State Superseded
Delegated to: Jeff Kirsher
Headers show
Series [S23,v2,01/15] ice: Implement ethtool ops for channels | expand

Commit Message

Tony Nguyen June 28, 2019, 3:03 p.m. UTC 
From: Mitch Williams <mitch.a.williams@intel.com>

In some circumstances, the hardware will hand us a receive descriptor
which has no data attached, but is otherwise valid. The receive code was
improperly ignoring these descriptors, which result in an infinite loop.

To fix this, change the receive code to process all descriptors,
regardless of the size of the associated data. Add checks to the
memory-handling functions to allow for zero size.

Signed-off-by: Mitch Williams <mitch.a.williams@intel.com>
---
 drivers/net/ethernet/intel/ice/ice_txrx.c | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

Comments

Bowers, AndrewX July 3, 2019, 6:15 p.m. UTC | #1 
> -----Original Message-----
> From: Intel-wired-lan [mailto:intel-wired-lan-bounces@osuosl.org] On
> Behalf Of Tony Nguyen
> Sent: Friday, June 28, 2019 8:03 AM
> To: intel-wired-lan@lists.osuosl.org
> Subject: [Intel-wired-lan] [PATCH S23 v2 08/15] ice: allow empty rx
> descriptors
> 
> From: Mitch Williams <mitch.a.williams@intel.com>
> 
> In some circumstances, the hardware will hand us a receive descriptor which
> has no data attached, but is otherwise valid. The receive code was
> improperly ignoring these descriptors, which result in an infinite loop.
> 
> To fix this, change the receive code to process all descriptors, regardless of
> the size of the associated data. Add checks to the memory-handling
> functions to allow for zero size.
> 
> Signed-off-by: Mitch Williams <mitch.a.williams@intel.com>
> ---
>  drivers/net/ethernet/intel/ice/ice_txrx.c | 19 +++++++++++++++----
>  1 file changed, 15 insertions(+), 4 deletions(-)

Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
diff mbox series

Patch

diff --git a/drivers/net/ethernet/intel/ice/ice_txrx.c b/drivers/net/ethernet/intel/ice/ice_txrx.c
index 1085ab920155..309207de1e86 100644
--- a/drivers/net/ethernet/intel/ice/ice_txrx.c
+++ b/drivers/net/ethernet/intel/ice/ice_txrx.c
@@ -859,6 +859,8 @@  ice_add_rx_frag(struct ice_rx_buf *rx_buf, struct sk_buff *skb,
 	unsigned int truesize = ICE_RXBUF_2048;
 #endif
 
+	if (!size)
+		return;
 	skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, rx_buf->page,
 			rx_buf->page_offset, size, truesize);
 
@@ -914,6 +916,8 @@  ice_get_rx_buf(struct ice_ring *rx_ring, struct sk_buff **skb,
 	prefetchw(rx_buf->page);
 	*skb = rx_buf->skb;
 
+	if (!size)
+		return rx_buf;
 	/* we are reusing so sync this buffer for CPU use */
 	dma_sync_single_range_for_cpu(rx_ring->dev, rx_buf->dma,
 				      rx_buf->page_offset, size,
@@ -1005,6 +1009,9 @@  static void ice_put_rx_buf(struct ice_ring *rx_ring, struct ice_rx_buf *rx_buf)
 	ntc = (ntc < rx_ring->count) ? ntc : 0;
 	rx_ring->next_to_clean = ntc;
 
+	if (!rx_buf)
+		return;
+
 	if (ice_can_reuse_rx_page(rx_buf)) {
 		/* hand second half of page back to the ring */
 		ice_reuse_rx_page(rx_ring, rx_buf);
@@ -1298,12 +1305,15 @@  static int ice_clean_rx_irq(struct ice_ring *rx_ring, int budget)
 		size = le16_to_cpu(rx_desc->wb.pkt_len) &
 			ICE_RX_FLX_DESC_PKT_LEN_M;
 
-		if (!size)
-			break;
-
 		/* retrieve a buffer from the ring */
 		rx_buf = ice_get_rx_buf(rx_ring, &skb, size);
 
+		if (!size) {
+			xdp.data = NULL;
+			xdp.data_end = NULL;
+			goto construct_skb;
+		}
+
 		xdp.data = page_address(rx_buf->page) + rx_buf->page_offset;
 		xdp.data_hard_start = xdp.data - ice_rx_offset(rx_ring);
 		xdp.data_end = xdp.data + size;
@@ -1342,7 +1352,8 @@  static int ice_clean_rx_irq(struct ice_ring *rx_ring, int budget)
 		/* exit if we failed to retrieve a buffer */
 		if (!skb) {
 			rx_ring->rx_stats.alloc_buf_failed++;
-			rx_buf->pagecnt_bias++;
+			if (rx_buf)
+				rx_buf->pagecnt_bias++;
 			break;
 		}