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Date: Tue, 9 Sep 2025 17:00:53 -0700
From: Jakub Kicinski <kuba@kernel.org>
To: Shenwei Wang <shenwei.wang@nxp.com>
Cc: Wei Fang <wei.fang@nxp.com>, Andrew Lunn <andrew+netdev@lunn.ch>, "David
 S. Miller" <davem@davemloft.net>, Eric Dumazet <edumazet@google.com>, Paolo
 Abeni <pabeni@redhat.com>, Alexei Starovoitov <ast@kernel.org>, Daniel
 Borkmann <daniel@iogearbox.net>, Jesper Dangaard Brouer <hawk@kernel.org>,
 John Fastabend <john.fastabend@gmail.com>, Clark Wang
 <xiaoning.wang@nxp.com>, Stanislav Fomichev <sdf@fomichev.me>,
 imx@lists.linux.dev, netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
 linux-imx@nxp.com, Andrew Lunn <andrew@lunn.ch>, Frank Li
 <frank.li@nxp.com>
Subject: Re: [PATCH v6 net-next 1/6] net: fec: use a member variable for
 maximum buffer size
Message-ID: <20250909170053.6d0eb1b7@kernel.org>
In-Reply-To: <20250908161755.608704-2-shenwei.wang@nxp.com>
References: <20250908161755.608704-1-shenwei.wang@nxp.com>
	<20250908161755.608704-2-shenwei.wang@nxp.com>
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On Mon,  8 Sep 2025 11:17:50 -0500 Shenwei Wang wrote:
> -#define	OPT_FRAME_SIZE	(PKT_MAXBUF_SIZE << 16)
> -#else
> -#define	OPT_FRAME_SIZE	0
> +#define	OPT_ARCH_HAS_MAX_FL
>  #endif

> +#ifdef OPT_ARCH_HAS_MAX_FL
> +	rcntl |= fep->max_buf_size << 16;
> +#endif

We try to avoid ifdefs inside C functions, they make compilation
coverage harder. Could you define OPT_ARCH_HAS_MAX_FL to 0 or 1
depending on the platform, and then use:

	if (OPT_ARCH_HAS_MAX_FL)
		rcntl |= fep->max_buf_size << 16;

The compiler will eliminate the condition if it's a constant,
but its slightly easier to read and lets the compiler see the code
regardless of the arch.