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 1BAB02FE58E; Mon, 27 Oct 2025 12:35:02 +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=1761568504; cv=none; b=ZMzTXcLIi0iwSP/YTGtO44woSbTE3rAfEq8oO3v0eYy692vHvZ++lTS8kxIQT/0lNvE8K+Xnr9cMsPExVDNzLa0I8JYSLd142cQ0cqmLu5N3Bgn+QmxVbulLBtNrXyxfceCgj2TMWh2Xr4y3sMEiXg0CRNc8U55WD3s06Hpg588= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761568504; c=relaxed/simple; bh=P+3UXldEAR7K0LP2DEUeWZ6b1BjyHAZunBfUNmacYL8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=V9L2TU0PCXbRYxwfpBGfR7DNxCk1ZqVonziCycDvggLlu3AXZYbuDJZmdUJLDaMjgmdx02Q/Rog9gryTGXlZvzaCZKMPbtEZLABw32Zzpsq52h7wzazpUt0f0ZP/I5g5h3qLVTbWt68YCNQshQaMLUV2m76rcEBgKMSpOzYz6DU= 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=xOHj51J/; 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="xOHj51J/" 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=iA7t2Iu5WmijCKzI4GOFbP1+sQVyXkrlu3SiinRY5fE=; b=xOHj51J/BGH7TW8B1tue9x+1cZ ciRjmO0LOkcfCgqKGjCBlhej8qpS2adZBtz83L4kTWr2SWApaY5YfMZ2y2Ezd/LwY8+ytZgOHpVEC 5g2JJQlARRG/mEHbQFcddVjttfvRkuIDkru5t5BQhF1yh4cYwCY8enA2+QPSZI+5AZyY=; Received: from andrew by vps0.lunn.ch with local (Exim 4.94.2) (envelope-from ) id 1vDMQs-00CBov-Nc; Mon, 27 Oct 2025 13:34:42 +0100 Date: Mon, 27 Oct 2025 13:34:42 +0100 From: Andrew Lunn To: Jacky Chou Cc: BMC-SW , Arnd Bergmann , "andrew+netdev@lunn.ch" , "davem@davemloft.net" , "edumazet@google.com" , "kuba@kernel.org" , "pabeni@redhat.com" , "robh@kernel.org" , "krzk+dt@kernel.org" , "conor+dt@kernel.org" , "joel@jms.id.au" , "andrew@codeconstruct.com.au" , "hkallweit1@gmail.com" , "linux@armlinux.org.uk" , "netdev@vger.kernel.org" , "devicetree@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-aspeed@lists.ozlabs.org" , "linux-kernel@vger.kernel.org" Subject: Re: =?utf-8?B?5Zue6KaG?= =?utf-8?Q?=3A?= [net-next 0/3] Add Aspeed G7 MDIO support Message-ID: References: <20241118104735.3741749-1-jacky_chou@aspeedtech.com> <7368c77e-08fe-4130-9b62-f1008cb5a0dc@lunn.ch> Precedence: bulk X-Mailing-List: linux-kernel@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: On Mon, Oct 27, 2025 at 02:44:23AM +0000, Jacky Chou wrote: > Hi Andrew, > > This is Jacky from ASPEED. > Last year, I submitted a series of patches to add a new compatible string > "aspeed,ast2700-mdio". At that time, the feedback I received was that if there > were no functional changes, a new compatible string would not be necessary. > Recently, we are submitting the AST2700 platform support to the Linux kernel. > In the following discussion thread, it appears that the MDIO driver might need > a new compatible string for the AST2700 platform: > https://lore.kernel.org/all/b048afc1-a143-4fd0-94c9-3677339d7f56@lunn.ch/ > I would like to confirm whether this case should be submitted separately to > net-next, and in general, if there are no hardware or design changes, is it > still required to introduce a new compatible string? Are you sure it is identical? And are you sure there are no bugs in the driver which would require breaking backwards compatibility, like you are going to be doing for the MAC driver? Take the reset handling for example. It looks like it was added after basic support for the 2600 has added, so it had to be optional, to not break backwards compatibility with older DT blobs. But since there is no support for the 2700 yet, you could make the reset mandatory, without breaking anything. How is the clock handled on this hardware? The MDC is currently ticking at 2.5MHz. However many PHYs and MDIO based Ethernet switches will happy run at a faster speed. So you could implemented 'clock-frequency'. But for that, do you need a clock listed? Should that clock be listed now, as a mandatory property for the 2700? Having a specific compatible and a fallback costs nothing, so i would do it. Andrew