Re: [PATCH net] net: mscc: fix the injection header

[Alexandre Belloni]

On 20/06/2018 10:50:46+0200, Antoine Ténart wrote:
> When injecting frames in the Ocelot switch driver an injection header
> (IFH) should be used to configure various parameters related to a given
> frame, such as the port onto which the frame should be departed or its
> vlan id. Other parameters in the switch configuration can led to an
> injected frame being sent without an IFH but this led to various issues
> as the per-frame parameters are then not used. This is especially true
> when using multiple ports for injection.
> 
> The IFH was injected with the wrong endianness which led to the switch
> not taking it into account as the IFH_INJ_BYPASS bit was then unset.
> (The bit tells the switch to use the IFH over its internal
> configuration). This patch fixes it.
> 
> In addition to the endianness fix, the IFH is also fixed. As it was
> (unwillingly) unused, some of its fields were not configured the right
> way.
> 
> Fixes: a556c76adc05 ("net: mscc: Add initial Ocelot switch support")
> Signed-off-by: Antoine Tenart <antoine.tenart@xxxxxxxxxxx>
Reviewed-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>

> ---
>  drivers/net/ethernet/mscc/ocelot.c | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/net/ethernet/mscc/ocelot.c b/drivers/net/ethernet/mscc/ocelot.c
> index fb2c8f8071e6..52c57e0ff617 100644
> --- a/drivers/net/ethernet/mscc/ocelot.c
> +++ b/drivers/net/ethernet/mscc/ocelot.c
> @@ -344,10 +344,9 @@ static int ocelot_port_stop(struct net_device *dev)
>  static int ocelot_gen_ifh(u32 *ifh, struct frame_info *info)
>  {
>  	ifh[0] = IFH_INJ_BYPASS;
> -	ifh[1] = (0xff00 & info->port) >> 8;
> +	ifh[1] = (0xf00 & info->port) >> 8;
>  	ifh[2] = (0xff & info->port) << 24;
> -	ifh[3] = IFH_INJ_POP_CNT_DISABLE | (info->cpuq << 20) |
> -		 (info->tag_type << 16) | info->vid;
> +	ifh[3] = (info->tag_type << 16) | info->vid;
>  
>  	return 0;
>  }
> @@ -370,11 +369,12 @@ static int ocelot_port_xmit(struct sk_buff *skb, struct net_device *dev)
>  			 QS_INJ_CTRL_SOF, QS_INJ_CTRL, grp);
>  
>  	info.port = BIT(port->chip_port);
> -	info.cpuq = 0xff;
> +	info.tag_type = IFH_TAG_TYPE_C;
> +	info.vid = skb_vlan_tag_get(skb);
>  	ocelot_gen_ifh(ifh, &info);
>  
>  	for (i = 0; i < IFH_LEN; i++)
> -		ocelot_write_rix(ocelot, ifh[i], QS_INJ_WR, grp);
> +		ocelot_write_rix(ocelot, cpu_to_be32(ifh[i]), QS_INJ_WR, grp);
>  
>  	count = (skb->len + 3) / 4;
>  	last = skb->len % 4;
> -- 
> 2.17.1
> 

-- 
Alexandre Belloni, Bootlin (formerly Free Electrons)
Embedded Linux and Kernel engineering
https://bootlin.com