Re: [dpdk-dev] [PATCH] fm10k: fix wrong VLAN value in RX mbuf

["He, Shaopeng" <shaopeng.he@intel.com>]

Hi, Stephen

> -----Original Message-----
> From: Stephen Hemminger [mailto:stephen@networkplumber.org]
> Sent: Friday, November 20, 2015 1:26 AM
> To: He, Shaopeng
> Cc: dev@dpdk.org
> Subject: Re: [dpdk-dev] [PATCH] fm10k: fix wrong VLAN value in RX mbuf
> 
> On Wed, 18 Nov 2015 16:50:09 +0800
> Shaopeng He <shaopeng.he@intel.com> wrote:
> 
> > VLAN value should be copied from RX descriptor to mbuf, this patch
> > fixes this issue.
> >
> > Signed-off-by: Shaopeng He <shaopeng.he@intel.com>
> > ---
> >  drivers/net/fm10k/fm10k_rxtx.c | 2 ++
> >  1 file changed, 2 insertions(+)
> >
> > diff --git a/drivers/net/fm10k/fm10k_rxtx.c
> > b/drivers/net/fm10k/fm10k_rxtx.c index 1bac28d..eeb635e 100644
> > --- a/drivers/net/fm10k/fm10k_rxtx.c
> > +++ b/drivers/net/fm10k/fm10k_rxtx.c
> > @@ -146,6 +146,7 @@ fm10k_recv_pkts(void *rx_queue, struct rte_mbuf
> > **rx_pkts,  #endif
> >
> >  		mbuf->hash.rss = desc.d.rss;
> > +		mbuf->vlan_tci = desc.w.vlan &
> FM10K_RXD_VLAN_ID_MASK;
> >
> >  		rx_pkts[count] = mbuf;
> >  		if (++next_dd == q->nb_desc) {
> > @@ -292,6 +293,7 @@ fm10k_recv_scattered_pkts(void *rx_queue, struct
> rte_mbuf **rx_pkts,
> >  		rx_desc_to_ol_flags(first_seg, &desc);  #endif
> >  		first_seg->hash.rss = desc.d.rss;
> > +		first_seg->vlan_tci = desc.w.vlan &
> FM10K_RXD_VLAN_ID_MASK;
> >
> >  		/* Prefetch data of first segment, if configured to do so. */
> >  		rte_packet_prefetch((char *)first_seg->buf_addr +
> 
> Good catch, this bug means VLAN's would not work right now.
> But I think it isn't quite right.

Actually, VLAN filter works well, only the vlan_tci in mbuf has wrong value.
And because not much places use the vlan_tci, this bug was not
found  before.

> 
> By masking the VLAN you are losing the received priority bits.
> Other drivers like ixgbe preserve the priority bits.

Yes, you are right, in next version, I will preserve the priority bits like others.

Thanks,
--Shaopeng