From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from vps0.lunn.ch (vps0.lunn.ch [156.67.10.101]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1DA1AF4F1; Wed, 5 Aug 2026 20:57:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=156.67.10.101 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785963477; cv=none; b=VkmkD6gO0cR50w4vsEKPzTbObsXEkmlOPKvyDc5xp1q4ToHDkyLrWmrLVZP2RVXyUFtnNiKF2aVtNuaJvFxcp0Hr5g44/ajITt+3gNM6bjOYsi0m85k+vhYpcthyUtU+NT6Xw85KLV8hlRty2UJbVZARyh3wOp1bcg0cjtLu25c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785963477; c=relaxed/simple; bh=wTPV/gz4ds+t1PfT36WfQEB9gHGJR8JiU761sqC6ews=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=MmImWHOZHcrZYMpdy6BdyVsSMcAve+Kf4HTJz8KrDumYMKQWT/DDo1tPnr/2//XizhjiSIsewul0V+QUgwnDKQ7TZRprEn4KeSl6z7A53MBp/qrx5Lsax/kig4NAwEA+sc/V9umZ0mAODIqzM+d+/EI4WkE7plo7BA6TGFo4J0k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lunn.ch; spf=pass smtp.mailfrom=lunn.ch; dkim=pass (1024-bit key) header.d=lunn.ch header.i=@lunn.ch header.b=yOFjryBm; arc=none smtp.client-ip=156.67.10.101 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lunn.ch Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=lunn.ch Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=lunn.ch header.i=@lunn.ch header.b="yOFjryBm" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lunn.ch; s=20171124; h=In-Reply-To:Content-Disposition:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:From:Sender:Reply-To:Subject: Date:Message-ID:To:Cc:MIME-Version:Content-Type:Content-Transfer-Encoding: Content-ID:Content-Description:Content-Disposition:In-Reply-To:References; bh=67FkVR7zlxPkd3JcEtzFf+ZKSYXXSY0vO0kegPJBHJw=; b=yOFjryBmU79qP3ZIqXABhJZL7i cJ53egEN+dQXvgUQXHwrWztDNzYXy7szzTXQLublurjx1D7vRLm0bgdOn7PBktWuO8DFODU9D/kvN tMQ5cY3tEWSn1lpn0fkc4d+Yi2Lv6mSGM4w6fy0Io9d5ol8PVhhT1ubGtYStPxCg19YU=; Received: from andrew by vps0.lunn.ch with local (Exim 4.94.2) (envelope-from ) id 1wrigF-00GFkk-O9; Wed, 05 Aug 2026 22:57:39 +0200 Date: Wed, 5 Aug 2026 22:57:39 +0200 From: Andrew Lunn To: =?iso-8859-1?Q?Th=E9o?= Lebrun Cc: "Polak, Leszek" , "andrew+netdev@lunn.ch" , "davem@davemloft.net" , "edumazet@google.com" , "kuba@kernel.org" , "pabeni@redhat.com" , "conor.dooley@microchip.com" , "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH] net: macb: fix stale data returned by MDIO reads Message-ID: <970df4d9-6199-4148-840a-ed1897ff27eb@lunn.ch> References: Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: > 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