From 9383b33771e566fa547daa2d09c6e0f1aaa298c3 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Thu, 2 Mar 2017 15:26:20 -0800 Subject: [PATCH] nfp: don't tell FW about the reserved buffer space Since commit c0f031bc8866 ("nfp_net: use alloc_frag() and build_skb()") we are allocating buffers which have to hold both the data and skb to be created in place by build_skb(). FW should only be told about the buffer space it can DMA to, that is without the build_skb() headroom and tailroom. Note: firmware applications should validate the buffers against both MTU and free list buffer size so oversized packets would not pass through the NIC anyway. Fixes: c0f031bc8866 ("nfp: use alloc_frag() and build_skb()") Signed-off-by: Jakub Kicinski Signed-off-by: David S. Miller --- drivers/net/ethernet/netronome/nfp/nfp_net_common.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c index 074259cc8e06..00a83218857a 100644 --- a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c +++ b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c @@ -2198,7 +2198,8 @@ static int __nfp_net_set_config_and_enable(struct nfp_net *nn) nfp_net_write_mac_addr(nn); nn_writel(nn, NFP_NET_CFG_MTU, nn->netdev->mtu); - nn_writel(nn, NFP_NET_CFG_FLBUFSZ, nn->fl_bufsz); + nn_writel(nn, NFP_NET_CFG_FLBUFSZ, + nn->fl_bufsz - NFP_NET_RX_BUF_NON_DATA); /* Enable device */ new_ctrl |= NFP_NET_CFG_CTRL_ENABLE;