From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pandora.armlinux.org.uk (pandora.armlinux.org.uk [78.32.30.218]) (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 7FDB73358D1 for ; Mon, 1 Dec 2025 16:38:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=78.32.30.218 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764607118; cv=none; b=l/TrS7lpMMdBLX06jnnBeefG6Jx+9GtccjFAIVBlHi/WdFoXdjC6/V258H0XMDb6dbolkqpS7NiUMBSiv/tJHfaf0D49JkJIjtMQZreEMOb8Q8OnyoHVzUq+Yp02rFkdaCsEVGmqUfzmYtBMbEqNLgc9cCjhZTpVS1+Sa8SZev4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764607118; c=relaxed/simple; bh=mAC0YZyitBsZeGGDTbwOudrYWr2Ek14k9InI/n+9Kr8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ewpPAeN1/S4UCnwZ2YQ5swwJ7eYcUYga0Fk2m62pZcrT/zDN216pHwPLbWSFLcEqT1zhawto0zfc1+AdMdNWavBl1wkjPRZchXXpa7TPHoIygoTm/2QktetFfWib1nHaCzXa53CA8lqILaWf5xJwMBQKjnBr7K1eSGSLk79C8Lk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=armlinux.org.uk; spf=none smtp.mailfrom=armlinux.org.uk; dkim=pass (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b=bSjgtfRi; arc=none smtp.client-ip=78.32.30.218 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=armlinux.org.uk Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=armlinux.org.uk Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b="bSjgtfRi" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=kGl7SM2seAnZb0MwfSY+i9t4y1zT3BYhdFJfFDtJktw=; b=bSjgtfRiEoSeXqz5HE779+QRoV MgpQsNPROlusFGq9HSqlAQXT0zvARqbLusTkXBhgPONL7nuUA1UT2d6LrQBTYrNO9rOypoGXtpPTJ 8XsDYxgkOrV7g+OpGYymsoHIY2uEFKj9fHc6UYs4mHUGfTmLqxeh1GUl1C7CsP2IpLaRrRbrwzFru RCXc4BKcri3pV1hEWttMzdzMcbxpmlCA/Ul/Rm0U7Kr2JIlTAnOXRYy3FR8MCH+PvawcjdhCS95Bv m+VEBkb8B/6yh71ijhfUDnhZFKSeAeDnly7BlxHcF7QRvJ4jdpqFrlSt376vlvkdCfEuDfd1Yctmt Ndj2yauQ==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:52260) by pandora.armlinux.org.uk with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.98.2) (envelope-from ) id 1vQ6uw-000000000pK-01R0; Mon, 01 Dec 2025 16:38:26 +0000 Received: from linux by shell.armlinux.org.uk with local (Exim 4.98.2) (envelope-from ) id 1vQ6us-000000006bg-1DIa; Mon, 01 Dec 2025 16:38:22 +0000 Date: Mon, 1 Dec 2025 16:38:22 +0000 From: "Russell King (Oracle)" To: Andrew Lunn Cc: Heiner Kallweit , Alexandre Torgue , Andrew Lunn , "David S. Miller" , Eric Dumazet , Heiko Stuebner , Jakub Kicinski , linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org, linux-stm32@st-md-mailman.stormreply.com, Maxime Coquelin , netdev@vger.kernel.org, Paolo Abeni Subject: Re: [PATCH RFC net-next 00/15] net: stmmac: rk: cleanups galore Message-ID: References: <05db9d3e-88fa-42db-8731-b77039c60efa@lunn.ch> 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: <05db9d3e-88fa-42db-8731-b77039c60efa@lunn.ch> Sender: Russell King (Oracle) On Mon, Dec 01, 2025 at 04:55:21PM +0100, Andrew Lunn wrote: > > One of the interesting things is that this appears to deal with RGMII > > delays at the MAC end of the link, but there's no way to tell phylib > > that's the case. I've not looked deeply into what is going on there, > > but it is surprising that the driver insists that the delays (in > > register values?) are provided, but then ignores them depending on the > > exact RGMII mode selected. > > Yes, many Rockchip .dts files use phy-mode = 'rgmii', and then do the > delays in the MAC. I've been pushing back on this for a while now, and > in most cases, it is possible to set the delays to 0, and use > 'rgmii-id'. > > Unfortunately, the vendor version of the driver comes with a debugfs > interface which puts the PHY into loopback, and then steps through the > different delay values to find the range of values which result in no > packet loss. The vendor documentation then recommends > phy-mode='rgmii', and set the delays to the middle value for this > range. So the vendor is leading developers up the garden path. > > These delay values also appear to be magical. There has been at least > one attempt to reverse engineer the values back to ns, but it was not > possible to get consistent results across a collection of boards. Oh yes, I remember that. I also remember that I had asked for the re-use of "phy_power_on()" to be fixed: https://lore.kernel.org/netdev/aDne1Ybuvbk0AwG0@shell.armlinux.org.uk/ but that never happened... which makes me wonder whether we *shouldn't* have applied "sensor101"'s patch until such a requested patch was available. In my experience, this is the standard behaviour - as a reviewer, you ask a contributor to do something as part of their patch submission, and as long as their patch gets merged, they couldn't give a monkeys about your request. So, in future, I'm going to take the attitude that I will NAK contributions if I think there's a side issue that the contributor should also be addressing until that side issue is addressed. This shouldn't be necessary, I wish this weren't necessary, and I wish people could be relied upon to do the right thing, but apparently it is going to take a stick (not merging their patches) to get them to co- operate. More fool me for trusting someone to do something. I now have a couple of extra patches addressing my point raised in that email... which I myself shouldn't have had to write. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!