RE: [PATCH 3/3] ocelot_ace: fix action of trap

From: "Y.b. Lu" <yangbo.lu@nxp.com>
To: "Allan W. Nielsen" <allan.nielsen@microchip.com>
Cc: "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
	"David S . Miller" <davem@davemloft.net>,
	Alexandre Belloni <alexandre.belloni@bootlin.com>,
	Microchip Linux Driver Support <UNGLinuxDriver@microchip.com>
Subject: RE: [PATCH 3/3] ocelot_ace: fix action of trap
Date: Tue, 13 Aug 2019 02:12:47 +0000	[thread overview]
Message-ID: <VI1PR0401MB223773EB5884D65890BD68C0F8D20@VI1PR0401MB2237.eurprd04.prod.outlook.com> (raw)
In-Reply-To: <20190812123147.6jjd3kocityxbvcg@lx-anielsen.microsemi.net>

Hi Allan,

> -----Original Message-----
> From: Allan W. Nielsen <allan.nielsen@microchip.com>
> Sent: Monday, August 12, 2019 8:32 PM
> To: Y.b. Lu <yangbo.lu@nxp.com>
> Cc: netdev@vger.kernel.org; David S . Miller <davem@davemloft.net>;
> Alexandre Belloni <alexandre.belloni@bootlin.com>; Microchip Linux Driver
> Support <UNGLinuxDriver@microchip.com>
> Subject: Re: [PATCH 3/3] ocelot_ace: fix action of trap
> 
> The 08/12/2019 18:48, Yangbo Lu wrote:
> > The trap action should be copying the frame to CPU and dropping it for
> > forwarding, but current setting was just copying frame to CPU.
> 
> Are there any actions which do a "copy-to-cpu" and still forward the frame in
> HW?

[Y.b. Lu] We're using Felix switch whose code hadn't been accepted by upstream.
https://patchwork.ozlabs.org/project/netdev/list/?series=115399&state=*

I'd like to trap all IEEE 1588 PTP Ethernet frames to CPU through etype 0x88f7.
When I used current TRAP option, I found the frames were not only copied to CPU, but also forwarded to other ports.
So I just made the TRAP option same with DROP option except enabling CPU_COPY_ENA in the patch.

Thanks.

> 
> > Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
> > ---
> >  drivers/net/ethernet/mscc/ocelot_ace.c | 6 +++---
> >  1 file changed, 3 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/net/ethernet/mscc/ocelot_ace.c
> > b/drivers/net/ethernet/mscc/ocelot_ace.c
> > index 91250f3..59ad590 100644
> > --- a/drivers/net/ethernet/mscc/ocelot_ace.c
> > +++ b/drivers/net/ethernet/mscc/ocelot_ace.c
> > @@ -317,9 +317,9 @@ static void is2_action_set(struct vcap_data *data,
> >  		break;
> >  	case OCELOT_ACL_ACTION_TRAP:
> >  		VCAP_ACT_SET(PORT_MASK, 0x0);
> > -		VCAP_ACT_SET(MASK_MODE, 0x0);
> > -		VCAP_ACT_SET(POLICE_ENA, 0x0);
> > -		VCAP_ACT_SET(POLICE_IDX, 0x0);
> > +		VCAP_ACT_SET(MASK_MODE, 0x1);
> > +		VCAP_ACT_SET(POLICE_ENA, 0x1);
> > +		VCAP_ACT_SET(POLICE_IDX, OCELOT_POLICER_DISCARD);
> This seems wrong. The policer is used to ensure that traffic are discarded, even
> in the case where other users of the code has requested it to go to the CPU.
> 
> Are you sure this is working? If it is working, then I fear we have an issue with
> the DROP action which uses this to discard frames.
> 
> >  		VCAP_ACT_SET(CPU_QU_NUM, 0x0);
> >  		VCAP_ACT_SET(CPU_COPY_ENA, 0x1);
> >  		break;
> > --
> > 2.7.4
> 
> --
> /Allan