From ac6f733a7bd5e23ce9d58ef995f51fbd1ad2fa97 Mon Sep 17 00:00:00 2001 From: Mitch Williams Date: Thu, 25 Jul 2019 01:55:34 -0700 Subject: [PATCH] ice: allow empty Rx descriptors 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 Tested-by: Andrew Bowers Signed-off-by: Jeff Kirsher --- drivers/net/ethernet/intel/ice/ice_txrx.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/drivers/net/ethernet/intel/ice/ice_txrx.c b/drivers/net/ethernet/intel/ice/ice_txrx.c index c88e0701e1d7..e5c4c9139e54 100644 --- a/drivers/net/ethernet/intel/ice/ice_txrx.c +++ b/drivers/net/ethernet/intel/ice/ice_txrx.c @@ -607,6 +607,8 @@ 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); @@ -662,6 +664,8 @@ 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, @@ -745,8 +749,11 @@ ice_construct_skb(struct ice_ring *rx_ring, struct ice_rx_buf *rx_buf, */ static void ice_put_rx_buf(struct ice_ring *rx_ring, struct ice_rx_buf *rx_buf) { - /* hand second half of page back to the ring */ + 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); rx_ring->rx_stats.page_reuse_count++; } else { @@ -1031,8 +1038,9 @@ 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; + /* retrieve a buffer from the ring */ rx_buf = ice_get_rx_buf(rx_ring, &skb, size); - /* allocate (if needed) and populate skb */ + if (skb) ice_add_rx_frag(rx_buf, skb, size); else @@ -1041,7 +1049,8 @@ 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; }