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Date: Sat, 11 May 2024 16:29:47 +0200
From: Andrew Lunn <andrew@lunn.ch>
To: Wei Fang <wei.fang@nxp.com>
Cc: davem@davemloft.net, edumazet@google.com, kuba@kernel.org,
	pabeni@redhat.com, shenwei.wang@nxp.com, xiaoning.wang@nxp.com,
	richardcochran@gmail.com, netdev@vger.kernel.org,
	linux-kernel@vger.kernel.org, imx@lists.linux.dev
Subject: Re: [PATCH v2 net-next] net: fec: Convert fec driver to use lock
 guards
Message-ID: <b96822ea-4373-415d-8397-d8bc5da88120@lunn.ch>
References: <20240511030229.628287-1-wei.fang@nxp.com>
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In-Reply-To: <20240511030229.628287-1-wei.fang@nxp.com>

On Sat, May 11, 2024 at 11:02:29AM +0800, Wei Fang wrote:
> The Scope-based resource management mechanism has been introduced into
> kernel since the commit 54da6a092431 ("locking: Introduce __cleanup()
> based infrastructure"). The mechanism leverages the 'cleanup' attribute
> provided by GCC and Clang, which allows resources to be automatically
> released when they go out of scope.
> Therefore, convert the fec driver to use guard() and scoped_guard()
> defined in linux/cleanup.h to automate lock lifetime control in the
> fec driver.

Sorry, it has been decided for netdev we don't want these sort of
conversions, at least not yet. The main worry is backporting fixes. It
is likely such bcakports are going to be harder, and also more error
prone, since the context is quite different.

If done correctly, scoped_guard() {} could be useful, and avoid
issues. So we are O.K. with that in new code. That will also allow us
to get some experience with it over the next few years. Maybe we will
then re-evaluate this decision about converting existing code.

    Andrew

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