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 1263F7080D; Mon, 3 Mar 2025 17:50:57 +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=1741024259; cv=none; b=i2QwMs7INjqbtef5vUT+14OzjHA2t5Aum+tGDNDOWgfnnLCbkfyIZFKCbQX/DBRE4s4GkAjl3clfBMc4zBFd1LZFHeAufq+VuAgA1STI1Akb+JsV8yt8VikLDEKkfQDW9ZRCq1LEq+eQQyw2I07xpmxUgAQg0BKzlFsMFsLhrzY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741024259; c=relaxed/simple; bh=4a4DylWFZtP89NSJt52sEF+ChcJMSqjanMmdjU8UI4g=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ug763gFzN2s411PKVCYNEBGJfbjf74qw9b9wsSw8XedDTEUsu2+hfvm/2AcaylZyKKlWRRbXXcow+QjJsdz2KnPCg/XXg5MCH07VpHLU5jAbJebjGfT+JmGsxvVpvqYKAujWaIs7SDpaYvz6q3GYpJI5cy5ayMa/DbPZ36RJH1I= 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=ozbGXvPX; 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="ozbGXvPX" 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=huF4lJ/BDhlfRxE6DvC+Oa6ZyjzrFulRNSOG2HNOGSM=; b=ozbGXvPXA3PbbeMaw6SuFXfVPR 3u3QFXrjH3SWwOShLiyc3z8EnLJ4jzDA9Rn0GcdiVRj5pFkdIqQJYFRi3UFbKA0TGZ1AlLQemAQ2j Z2YyhJQQKjLundvEEo+MnAoRBj7VuyEQgSWvO0iFWuMqw52t+GPnhO0xeOsmSTpJ+okQ=; Received: from andrew by vps0.lunn.ch with local (Exim 4.94.2) (envelope-from ) id 1tp9wG-001sme-Bq; Mon, 03 Mar 2025 18:50:48 +0100 Date: Mon, 3 Mar 2025 18:50:48 +0100 From: Andrew Lunn To: Jean-Michel Hautbois Cc: Heiner Kallweit , Russell King , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Catalin Popescu , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] net: phy: dp83826: Add support for straps reading Message-ID: References: <20250303-dp83826-fixes-v1-0-6901a04f262d@yoseli.org> <20250303-dp83826-fixes-v1-2-6901a04f262d@yoseli.org> <7cd18e37-2d68-4825-bcc4-fc2ac6b9a461@yoseli.org> 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: <7cd18e37-2d68-4825-bcc4-fc2ac6b9a461@yoseli.org> On Mon, Mar 03, 2025 at 06:37:28PM +0100, Jean-Michel Hautbois wrote: > Hi Andrew, > > On 03/03/2025 18:20, Andrew Lunn wrote: > > On Mon, Mar 03, 2025 at 06:05:52PM +0100, Jean-Michel Hautbois wrote: > > > When the DP83826 is probed, read the straps, and apply the default > > > settings expected. The MDI-X is not yet supported, but still read the > > > strap. > > > > What about backwards compatibility? I expect this changes the > > behaviour of the device, potentially introducing regressions? Please > > add an explanation of why this is safe. > > I am not certain it is safe. As far as I know that if straps are used on the > hardware, then it should be used, and if the behavior has to be different, > then userspace can change it (or any other way). Am I wrong ? First off, what does the datasheet say about these straps? Straps generally configure the hardware, without software being involved. It seems odd you need software to read the straps and apply them. Why do you need this? What is your use case. As you said, user space can configure all this, so why are you not doing that? Andrew