From abe787170bb3888c5e587e8e986711fe32ddf2f9 Mon Sep 17 00:00:00 2001 From: Lennert Buytenhek Date: Sun, 24 Aug 2008 03:00:20 +0200 Subject: [PATCH] mv643xx_eth: enforce multiple-of-8-bytes receive buffer size restriction The mv643xx_eth hardware ignores the lower three bits of the buffer size field in receive descriptors, causing the reception of full-sized packets to fail at some MTUs. Fix this by rounding the size of allocated receive buffers up to a multiple of eight bytes. While we are at it, add a bit of extra space to each receive buffer so that we can handle multiple vlan tags on ingress. Signed-off-by: Lennert Buytenhek --- drivers/net/mv643xx_eth.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) diff --git a/drivers/net/mv643xx_eth.c b/drivers/net/mv643xx_eth.c index e33dfc0165f..a02a5f4a029 100644 --- a/drivers/net/mv643xx_eth.c +++ b/drivers/net/mv643xx_eth.c @@ -474,11 +474,19 @@ static void rxq_refill(struct rx_queue *rxq) /* * Reserve 2+14 bytes for an ethernet header (the * hardware automatically prepends 2 bytes of dummy - * data to each received packet), 4 bytes for a VLAN - * header, and 4 bytes for the trailing FCS -- 24 - * bytes total. + * data to each received packet), 16 bytes for up to + * four VLAN tags, and 4 bytes for the trailing FCS + * -- 36 bytes total. */ - skb_size = mp->dev->mtu + 24; + skb_size = mp->dev->mtu + 36; + + /* + * Make sure that the skb size is a multiple of 8 + * bytes, as the lower three bits of the receive + * descriptor's buffer size field are ignored by + * the hardware. + */ + skb_size = (skb_size + 7) & ~7; skb = dev_alloc_skb(skb_size + dma_get_cache_alignment() - 1); if (skb == NULL) @@ -552,7 +560,7 @@ static int rxq_process(struct rx_queue *rxq, int budget) spin_unlock_irqrestore(&mp->lock, flags); dma_unmap_single(NULL, rx_desc->buf_ptr + 2, - mp->dev->mtu + 24, DMA_FROM_DEVICE); + rx_desc->buf_size, DMA_FROM_DEVICE); rxq->rx_desc_count--; rx++; -- 2.41.1