From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5C5E8C25B08 for ; Thu, 18 Aug 2022 01:44:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242528AbiHRBok (ORCPT ); Wed, 17 Aug 2022 21:44:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48838 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235733AbiHRBoi (ORCPT ); Wed, 17 Aug 2022 21:44:38 -0400 Received: from vps0.lunn.ch (vps0.lunn.ch [185.16.172.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D6A83A1A74; Wed, 17 Aug 2022 18:44:34 -0700 (PDT) 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=v/ogUYGKhlL5A9QYZicl3oguBuH01CMBW+H2SPHWlcY=; b=OjN4bS215lSgFfYMQQiD3ZiDze 7k8YW41eft49l+Dspmjw/tCXJ1EXjQ+93EpaLaPeufaEe+x0TEn7W/ompuH8pSBzfnGMAQkAn61JH vCMSIvfftE40xU49pcEuZPQHjIqSAABOhHB8f/zAK7RSbFOQuv3+n44TcwXfZpmdprfU=; Received: from andrew by vps0.lunn.ch with local (Exim 4.94.2) (envelope-from ) id 1oOUa9-00Dgfw-Hb; Thu, 18 Aug 2022 03:44:25 +0200 Date: Thu, 18 Aug 2022 03:44:25 +0200 From: Andrew Lunn To: Wei Fang Cc: "hkallweit1@gmail.com" , "linux@armlinux.org.uk" , "davem@davemloft.net" , "edumazet@google.com" , "kuba@kernel.org" , "pabeni@redhat.com" , "robh+dt@kernel.org" , "krzysztof.kozlowski+dt@linaro.org" , "f.fainelli@gmail.com" , "netdev@vger.kernel.org" , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH net 1/2] dt: ar803x: Document disable-hibernation property Message-ID: References: <20220812145009.1229094-1-wei.fang@nxp.com> <20220812145009.1229094-2-wei.fang@nxp.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > Yes, after the PHY enters hibernation mode that the RX_CLK stop ticking, but > for stmmac, it is essential that RX_CLK of PHY is present for software reset > completion. Otherwise, the stmmac is failed to complete the software reset > and can not init DMA. So the RX_CLK is more than the recovered clock from the bit stream on the wire. The PHY has a way to generate a clock when there is no bit stream? To me, it sounds like your hardware design is wrong, and it should be using the 25MHz reference clock. And what you are proposing is a workaround for this hardware problem. Anyway, i agree with Russell, a DT property is fine. But please make it clear in the binding documentation that disabling hibernation has the side affect of keeping the RX_CLK ticking when there is no link. That is probably what people want this for, not to actual disable hibernation. Andrew