linux-kernel - Re: [PATCH v2 net-next 1/5] net: fec: use a member variable for maximum buffer size

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID:
 <PAXPR04MB9185504DE13B946FF38F3CEE8932A@PAXPR04MB9185.eurprd04.prod.outlook.com>
Date: Thu, 21 Aug 2025 20:54:33 +0000
From: Shenwei Wang <shenwei.wang@....com>
To: Andrew Lunn <andrew@...n.ch>
CC: Wei Fang <wei.fang@....com>, Andrew Lunn <andrew+netdev@...n.ch>, "David
 S. Miller" <davem@...emloft.net>, Eric Dumazet <edumazet@...gle.com>, Jakub
 Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>, Alexei
 Starovoitov <ast@...nel.org>, Daniel Borkmann <daniel@...earbox.net>, Jesper
 Dangaard Brouer <hawk@...nel.org>, John Fastabend <john.fastabend@...il.com>,
	Clark Wang <xiaoning.wang@....com>, Stanislav Fomichev <sdf@...ichev.me>,
	"imx@...ts.linux.dev" <imx@...ts.linux.dev>, "netdev@...r.kernel.org"
	<netdev@...r.kernel.org>, "linux-kernel@...r.kernel.org"
	<linux-kernel@...r.kernel.org>, dl-linux-imx <linux-imx@....com>
Subject: Re: [PATCH v2 net-next 1/5] net: fec: use a member variable for
 maximum buffer size



> -----Original Message-----
> From: Andrew Lunn <andrew@...n.ch>
> Sent: Thursday, August 21, 2025 1:56 PM
> To: Shenwei Wang <shenwei.wang@....com>
> Cc: Wei Fang <wei.fang@....com>; Andrew Lunn <andrew+netdev@...n.ch>;
> David S. Miller <davem@...emloft.net>; Eric Dumazet
> <edumazet@...gle.com>; Jakub Kicinski <kuba@...nel.org>; Paolo Abeni
> <pabeni@...hat.com>; Alexei Starovoitov <ast@...nel.org>; Daniel Borkmann
> <daniel@...earbox.net>; Jesper Dangaard Brouer <hawk@...nel.org>; John
> Fastabend <john.fastabend@...il.com>; Clark Wang
> <xiaoning.wang@....com>; Stanislav Fomichev <sdf@...ichev.me>;
> imx@...ts.linux.dev; netdev@...r.kernel.org; linux-kernel@...r.kernel.org; dl-
> linux-imx <linux-imx@....com>
> Subject: [EXT] Re: [PATCH v2 net-next 1/5] net: fec: use a member variable for
> maximum buffer size
> 
> > @@ -1145,9 +1145,12 @@ static void
> >  fec_restart(struct net_device *ndev)
> >  {
> >       struct fec_enet_private *fep = netdev_priv(ndev);
> > -     u32 rcntl = OPT_FRAME_SIZE | FEC_RCR_MII;
> > +     u32 rcntl = FEC_RCR_MII;
> >       u32 ecntl = FEC_ECR_ETHEREN;
> >
> > +     if (fep->max_buf_size == OPT_FRAME_SIZE)
> > +             rcntl |= (fep->max_buf_size << 16);
> 
> I was expecting something like s/OPT_FRAME_SIZE/fep->max_buf_size/g
> 
> This is introducing extra logic. I think the if (...) belongs in another patch. The
> assignment is however what i expected.

We just had an internal discussion and found that updating the macro definition is the simplest 
and most straightforward solution, as shown below. With this change, the above modifications 
are no longer necessary.

-#define        OPT_FRAME_SIZE  (PKT_MAXBUF_SIZE << 16)
+#define        OPT_FRAME_SIZE  (fep->max_buf_size << 16)
 #else
 #define        OPT_FRAME_SIZE  0

Thanks,
Shenwei

> 
>     Andrew
> 
> ---
> pw-bot: cr