Re: [PATCH 2/7] igb: take vlan double header into account

[Sven Auhagen <sven.auhagen@voleatech.de>]

On Wed, Oct 07, 2020 at 11:06:15PM +0200, Maciej Fijalkowski wrote:
> On Wed, Oct 07, 2020 at 05:25:01PM +0200, sven.auhagen@voleatech.de wrote:
> > From: Sven Auhagen <sven.auhagen@voleatech.de>
> > 
> > Increase the packet header padding to include double VLAN tagging.
> > This patch uses a macro for this.
> > 
> > Signed-off-by: Sven Auhagen <sven.auhagen@voleatech.de>
> > ---
> >  drivers/net/ethernet/intel/igb/igb.h      | 5 +++++
> >  drivers/net/ethernet/intel/igb/igb_main.c | 7 +++----
> >  2 files changed, 8 insertions(+), 4 deletions(-)
> > 
> > diff --git a/drivers/net/ethernet/intel/igb/igb.h b/drivers/net/ethernet/intel/igb/igb.h
> > index 0286d2fceee4..7afb67cf9b94 100644
> > --- a/drivers/net/ethernet/intel/igb/igb.h
> > +++ b/drivers/net/ethernet/intel/igb/igb.h
> > @@ -138,6 +138,8 @@ struct vf_mac_filter {
> >  /* this is the size past which hardware will drop packets when setting LPE=0 */
> >  #define MAXIMUM_ETHERNET_VLAN_SIZE 1522
> >  
> > +#define IGB_ETH_PKT_HDR_PAD	(ETH_HLEN + ETH_FCS_LEN + (VLAN_HLEN * 2))
> > +
> >  /* Supported Rx Buffer Sizes */
> >  #define IGB_RXBUFFER_256	256
> >  #define IGB_RXBUFFER_1536	1536
> > @@ -247,6 +249,9 @@ enum igb_tx_flags {
> >  #define IGB_SFF_ADDRESSING_MODE		0x4
> >  #define IGB_SFF_8472_UNSUP		0x00
> >  
> > +/* TX ressources are shared between XDP and netstack
> > + * and we need to tag the buffer type to distinguish them
> > + */
> 
> s/ressources/resources/
> 
> This comment sort of does not belong to this commit but I'm not sure what
> place would be better.

I had the same problem.
I don't think it is enough for an extra patch so I just added it here.
I fix the spelling.

> 
> >  enum igb_tx_buf_type {
> >  	IGB_TYPE_SKB = 0,
> >  	IGB_TYPE_XDP,
> > diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
> > index 08cc6f59aa2e..0a9198037b98 100644
> > --- a/drivers/net/ethernet/intel/igb/igb_main.c
> > +++ b/drivers/net/ethernet/intel/igb/igb_main.c
> > @@ -2826,7 +2826,7 @@ static int igb_setup_tc(struct net_device *dev, enum tc_setup_type type,
> >  
> >  static int igb_xdp_setup(struct net_device *dev, struct bpf_prog *prog)
> >  {
> > -	int i, frame_size = dev->mtu + ETH_HLEN + ETH_FCS_LEN + VLAN_HLEN;
> > +	int i, frame_size = dev->mtu + IGB_ETH_PKT_HDR_PAD;
> >  	struct igb_adapter *adapter = netdev_priv(dev);
> >  	bool running = netif_running(dev);
> >  	struct bpf_prog *old_prog;
> > @@ -3950,8 +3950,7 @@ static int igb_sw_init(struct igb_adapter *adapter)
> >  	/* set default work limits */
> >  	adapter->tx_work_limit = IGB_DEFAULT_TX_WORK;
> >  
> > -	adapter->max_frame_size = netdev->mtu + ETH_HLEN + ETH_FCS_LEN +
> > -				  VLAN_HLEN;
> > +	adapter->max_frame_size = netdev->mtu + IGB_ETH_PKT_HDR_PAD;
> >  	adapter->min_frame_size = ETH_ZLEN + ETH_FCS_LEN;
> >  
> >  	spin_lock_init(&adapter->nfc_lock);
> > @@ -6491,7 +6490,7 @@ static void igb_get_stats64(struct net_device *netdev,
> >  static int igb_change_mtu(struct net_device *netdev, int new_mtu)
> >  {
> >  	struct igb_adapter *adapter = netdev_priv(netdev);
> > -	int max_frame = new_mtu + ETH_HLEN + ETH_FCS_LEN + VLAN_HLEN;
> > +	int max_frame = new_mtu + IGB_ETH_PKT_HDR_PAD;
> >  
> >  	if (adapter->xdp_prog) {
> >  		int i;
> > -- 
> > 2.20.1
> >