RE: [PATCH net-next v2 13/14] ravb: Update EMAC configuration mode comment

Hi Sergey,

Thanks for the suggestion.

Subject: RE: [PATCH net-next v2 13/14] ravb: Update EMAC configuration
mode comment

quoted

-----Original Message-----
From: Sergei Shtylyov <redacted>
Sent: 10 October 2021 10:49
To: Biju Das <biju.das.jz@bp.renesas.com>; David S. Miller
[off-list ref]; Jakub Kicinski [off-list ref]
Cc: Sergey Shtylyov <redacted>; Geert Uytterhoeven
[off-list ref]; Sergey Shtylyov [off-list ref];
Adam Ford [off-list ref]; Andrew Lunn [off-list ref]; Yuusuke
Ashizuka [off-list ref]; Yoshihiro Shimoda
[off-list ref]; netdev@vger.kernel.org;
linux-renesas- soc@vger.kernel.org; Chris Paterson
[off-list ref]; Biju Das [off-list ref];
Prabhakar Mahadev Lad <prabhakar.mahadev- lad.rj@bp.renesas.com>
Subject: Re: [PATCH net-next v2 13/14] ravb: Update EMAC configuration
mode comment

On 10.10.2021 12:37, Biju Das wrote:

quoted

Hi Sergey,

quoted

-----Original Message-----
From: Sergei Shtylyov <redacted>
Sent: 10 October 2021 10:28
To: Biju Das <biju.das.jz@bp.renesas.com>; David S. Miller
[off-list ref]; Jakub Kicinski [off-list ref]
Cc: Sergey Shtylyov <redacted>; Geert Uytterhoeven
[off-list ref]; Sergey Shtylyov
[off-list ref]; Adam Ford [off-list ref]; Andrew
Lunn [off-list ref]; Yuusuke Ashizuka [off-list ref];
Yoshihiro Shimoda [off-list ref];
netdev@vger.kernel.org;
linux-renesas- soc@vger.kernel.org; Chris Paterson
[off-list ref]; Biju Das [off-list ref];
Prabhakar Mahadev Lad <prabhakar.mahadev- lad.rj@bp.renesas.com>
Subject: Re: [PATCH net-next v2 13/14] ravb: Update EMAC
configuration mode comment

On 10.10.2021 10:29, Biju Das wrote:

quoted

Update EMAC configuration mode comment from "PAUSE prohibition"
to "EMAC Mode: PAUSE prohibition; Duplex; TX; RX; CRC Pass
Through; Promiscuous".

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Suggested-by: Sergey Shtylyov <redacted>
---
v1->v2:
   * No change
V1:
   * New patch.
---
   drivers/net/ethernet/renesas/ravb_main.c | 2 +-
   1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/renesas/ravb_main.c

b/drivers/net/ethernet/renesas/ravb_main.c
index 9a770a05c017..b78aca235c37 100644

--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c

@@ -519,7 +519,7 @@ static void ravb_emac_init_gbeth(struct

net_device

*ndev)

quoted

   	/* Receive frame limit set register */
   	ravb_write(ndev, GBETH_RX_BUFF_MAX + ETH_FCS_LEN, RFLR);

-	/* PAUSE prohibition */
+	/* EMAC Mode: PAUSE prohibition; Duplex; TX; RX; CRC Pass
+Through; Promiscuous */

     Promiscuous mode, really? Why?!

This is TOE related,

I meant the context here is TOE register related. That is what I meant.

quoted

    The promiscuous mode is supported by _all_ Ethernet controllers, I
think.

quoted

and is recommendation from BSP team.

    On what grounds?

The reference implementation has this on. Any way it is good catch.
I will turn it off and check.

by looking at the RJ LED's there is not much activity and packet
statistics also show not much activity by default.

How can we check, it is overloading the controller? So that I can compare
with and without this setting

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If you think it is wrong.
I can take this out. Please let me know. Currently the board is
booting

and everything works without issues.

    Please do take it out. It'll needlessly overload the controller
when there's much traffic on the local network.

I have tested without this as well and I don't find any difference.
So I plan to take this out.

Do you have any idea how to check the "overloading the controller" with PRM bit ON/OFF 
to check the actual impact? Please let me know, so that I can compare the same.

Regards,
Biju

I can see much activity only on RJ45 LED's when I call tcpdump or by
setting IP link set eth0 promisc on.
Otherwise there is no traffic at all.

Regards,
Biju

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The meaning of promiscuous in H/W manual as follows.

    I know what the promiscuous mode is. :-)
    It's needed by things like 'tcpdump' and normally shoild be off.

quoted

Promiscuous Mode
1: All the frames except for PAUSE frame are received.
Self-addressed unicast, different address unicast, multicast, and
broadcast frames are all transferred to TOE. PAUSE frame reception
is controlled by PFR

bit.

quoted

0: Self-addressed unicast, multicast, and broadcast frames are
received, then transferred to TOE.

quoted

quoted

Regards,
Biju

MBR, Sergey