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 12:00 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
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=aTgHva-UVEPl9EAR@shell.armlinux.org.uk \
--to=linux@armlinux.org.uk \
--cc=andrew@codeconstruct.com.au \
--cc=andrew@lunn.ch \
--cc=davem@davemloft.net \
--cc=edumazet@google.com \
--cc=hkallweit1@gmail.com \
--cc=jacky_chou@aspeedtech.com \
--cc=joel@jms.id.au \
--cc=kuba@kernel.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-aspeed@lists.ozlabs.org \
--cc=linux-kernel@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=pabeni@redhat.com \
--cc=potin.lai@quantatw.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.