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From: Jakub Kicinski <kuba@kernel.org>
To: Gui-Dong Han <hanguidong02@gmail.com>
Cc: Chris Snook <chris.snook@gmail.com>,
	Andrew Lunn <andrew+netdev@lunn.ch>,
	"David S . Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Paolo Abeni <pabeni@redhat.com>,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	baijiaju1990@gmail.com
Subject: Re: [PATCH] net: atheros: atl1e: use atomic functions with memory barriers for next_to_clean
Date: Mon, 27 Apr 2026 17:59:30 -0700	[thread overview]
Message-ID: <20260427175930.3c170c98@kernel.org> (raw)
In-Reply-To: <20260422093717.893646-1-hanguidong02@gmail.com>

On Wed, 22 Apr 2026 17:37:17 +0800 Gui-Dong Han wrote:
> Found by auditing atomic operations used for synchronization.
> A similar fix can be found in 6df8e84aa6b5.
> 
> Do not change atl1e_init_ring_ptrs(). Its atomic_set() runs during
> bring-up before NAPI and interrupts are enabled, so it is not a runtime
> publication point between Tx cleanup and Tx submission.
> 
> In my opinion, implementing ad-hoc lockless algorithms directly within
> individual drivers is highly error-prone. To avoid these subtle memory
> ordering and barrier bugs, drivers should rely on established, well-tested
> kernel libraries like kfifo to handle this type of concurrency.

I don't think this is sufficient, we can still race stop vs wake. 
Please convert the driver to use netif_txq_maybe_stop() and friends.
-- 
pw-bot: cr

      reply	other threads:[~2026-04-28  0:59 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-04-22  9:37 [PATCH] net: atheros: atl1e: use atomic functions with memory barriers for next_to_clean Gui-Dong Han
2026-04-28  0:59 ` Jakub Kicinski [this message]

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