From: "Russell King (Oracle)" <linux@armlinux.org.uk>
To: Jacky Chou <jacky_chou@aspeedtech.com>
Cc: Andrew Lunn <andrew@lunn.ch>,
Heiner Kallweit <hkallweit1@gmail.com>,
"David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
Joel Stanley <joel@jms.id.au>,
Andrew Jeffery <andrew@codeconstruct.com.au>,
Potin Lai <potin.lai@quantatw.com>,
netdev@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
linux-aspeed@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH net v2] net: mdio: aspeed: add dummy read to avoid read-after-write issue
Date: Tue, 9 Dec 2025 11:27:57 +0000 [thread overview]
Message-ID: <aTgHva-UVEPl9EAR@shell.armlinux.org.uk> (raw)
In-Reply-To: <20251209-aspeed_mdio_add_dummy_read-v2-1-5f6061641989@aspeedtech.com>
On Tue, Dec 09, 2025 at 07:15:31PM +0800, Jacky Chou wrote:
> + /* Workaround for read-after-write issue.
> + * The controller may return stale data if a read follows immediately
> + * after a write. A dummy read forces the hardware to update its
> + * internal state, ensuring that the next real read returns correct data.
> + */
> + (void)ioread32(ctx->base + ASPEED_MDIO_CTRL);
What purpose does this cast to void achieve in an already void context?
We have plenty of functions that get called in the kernel that return a
value which the caller ignores, never assigning to a variable, none of
these warn.
--
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!
next prev parent reply other threads:[~2025-12-09 11:28 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-12-09 11:15 [PATCH net v2] net: mdio: aspeed: add dummy read to avoid read-after-write issue Jacky Chou
2025-12-09 11:27 ` Russell King (Oracle) [this message]
2025-12-10 2:51 ` Jacky Chou
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