From: Andrew Lunn <andrew@lunn.ch>
To: "Théo Lebrun" <theo.lebrun@bootlin.com>
Cc: "Polak, Leszek" <LPolak@arri.de>,
"andrew+netdev@lunn.ch" <andrew+netdev@lunn.ch>,
"davem@davemloft.net" <davem@davemloft.net>,
"edumazet@google.com" <edumazet@google.com>,
"kuba@kernel.org" <kuba@kernel.org>,
"pabeni@redhat.com" <pabeni@redhat.com>,
"conor.dooley@microchip.com" <conor.dooley@microchip.com>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] net: macb: fix stale data returned by MDIO reads
Date: Wed, 5 Aug 2026 22:57:39 +0200 [thread overview]
Message-ID: <970df4d9-6199-4148-840a-ed1897ff27eb@lunn.ch> (raw)
In-Reply-To: <DKH3PSLM2LJ8.1S1B51A95T75M@bootlin.com>
> A proper solution would use the IRQ as detection source rather than
> sleep-polling. See BIT 0, called MFD in driver.
Maybe.
The FEC driver used to use interrupts for its MDIO bus. But interrupts
add a lot of overhead. I swapped the FEC to polling and got a
significant speed improvement.
A lot depends on what you have actually doing with the bus. I was
using it in combination with Marvell PHYs, which can give the raw
cable test values, which is a big data set. So the speed up was
welcome. But if all the bus is used for is once per second polls for
link change, a slower bus probably does not matter.
Andrew
prev parent reply other threads:[~2026-08-05 20:57 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-05 12:01 [PATCH] net: macb: fix stale data returned by MDIO reads Polak, Leszek
2026-08-05 14:45 ` Théo Lebrun
2026-08-05 14:52 ` Théo Lebrun
2026-08-05 15:05 ` Théo Lebrun
2026-08-05 20:57 ` Andrew Lunn [this message]
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