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

-----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.

    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

quoted

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 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

quoted

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

Regards,
Biju

MBR, Sergey