From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from relay5-d.mail.gandi.net (relay5-d.mail.gandi.net [217.70.183.197]) (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 E2703249EE; Sun, 4 Feb 2024 17:14:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.70.183.197 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707066886; cv=none; b=G5mYxdCQfao7/vTCoVDYfDwrVRmmHUZ6c/mVAa9qL0bVFse3MG7VjA9Mn8xJeftUy1Zx1AKHbGf31FBQNCBGuUataQvKf0W0YQO/pXg9KEXI3opZtefX8vP3L4WYxsc5U6sXPoio/Ng57wmp/V1JFghtZnRKETxVrAitAgwMNX0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707066886; c=relaxed/simple; bh=ufnpAJtjNlPY8LSmrUh8Ne15mi556Fg30IBELlzG22w=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=O1NJtsoLIn748mnK8xYMAt6JrITFwpurUsqTpGWxnYRAPDGZefQjkjLKBTigxRwVvqV3la0FNy6WqK0Tyx4Pk6RC8yY07aFs4eabvhQkh6tMu3qyDL+R2JtXCafwRRjyTcb3NAzbIY8aicxPWdSakbrMolV0qg2Rvm9MQqA6YV8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arinc9.com; spf=pass smtp.mailfrom=arinc9.com; dkim=pass (2048-bit key) header.d=arinc9.com header.i=@arinc9.com header.b=F1ga4EHC; arc=none smtp.client-ip=217.70.183.197 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arinc9.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arinc9.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=arinc9.com header.i=@arinc9.com header.b="F1ga4EHC" Received: by mail.gandi.net (Postfix) with ESMTPSA id 71C321C0004; Sun, 4 Feb 2024 17:14:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=arinc9.com; s=gm1; t=1707066875; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=K5upyVZOvpW2/geHP/GaiSZGDEybCBhpCuzrkfpNdl4=; b=F1ga4EHC3mh7g9nlACaFpYPo5+C81utzCbHu1mmSS7H1uaAg4K1jGIVkorJcOpUlKXUING cnpO2caNz17H6NM0cLEMGS4oJolHtcbF+EH3dDs5iqXoO2xyLmUsUOfdjPz9xnAllxzZag zjhpSXX3d+RmBRLPDdVERD8mdi0qAeJwyIG52PaBtCmO1ZNBA3wbQ2cN3fzo9JKC0lcrwG t+CnsJNdDNIpQNhjuefQNB0NUQTiXvdaaQNncn/5CiD0YTDcK+V3BSyDSSIjU3ybVDS0g2 GLy6nhwbjv8dUOv4QXSuIbJlugJ95uF48bGRB15vjDPgNNJ6jqVcLAun9X95hw== Message-ID: <24ce3ff9-22b3-4d5d-ade4-3b8521aeadfe@arinc9.com> Date: Sun, 4 Feb 2024 20:14:27 +0300 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH net-next v3 4/7] net: dsa: mt7530: move XTAL check to mt7530_setup() Content-Language: en-US To: "Russell King (Oracle)" Cc: Daniel Golle , DENG Qingfang , Sean Wang , Andrew Lunn , Florian Fainelli , Vladimir Oltean , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Matthias Brugger , AngeloGioacchino Del Regno , mithat.guner@xeront.com, erkin.bozoglu@xeront.com, Bartel Eerdekens , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org References: <20240202-for-netnext-mt7530-improvements-2-v3-0-63d5adae99ca@arinc9.com> <20240202-for-netnext-mt7530-improvements-2-v3-4-63d5adae99ca@arinc9.com> <5b744f7f-2f63-4219-a0e9-8f08267b1fdd@arinc9.com> <4fa2ff0d-2804-4a58-980f-162e62b3dc9c@arinc9.com> <850064fb-59c6-4e07-962a-6a213e9e7f90@arinc9.com> From: =?UTF-8?B?QXLEsW7DpyDDnE5BTA==?= In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-GND-Sasl: arinc.unal@arinc9.com On 4.02.2024 20:07, Russell King (Oracle) wrote: > On Sun, Feb 04, 2024 at 07:51:49PM +0300, Arınç ÜNAL wrote: >> On 4.02.2024 19:38, Russell King (Oracle) wrote: >>> On Sun, Feb 04, 2024 at 06:55:14PM +0300, Arınç ÜNAL wrote: >>>> On 4.02.2024 17:18, Russell King (Oracle) wrote: >>>>> On Sun, Feb 04, 2024 at 04:55:40PM +0300, Arınç ÜNAL wrote: >>>>>> This is not about laziness. This is before patch 2: >>>>>> >>>>>> phylink_mac_ops :: mac_config() -> dsa_port_phylink_mac_config() >>>>>> -> dsa_switch_ops :: phylink_mac_config() -> mt753x_phylink_mac_config() >>>>>> -> mt753x_mac_config() >>>>>> -> mt753x_info :: mac_port_config() -> mt7530_mac_config() >>>>>> -> mt7530_setup_port5() >>>>>> -> mt753x_pad_setup() >>>>>> -> mt753x_info :: pad_setup() -> mt7530_pad_clk_setup() >>>>>> >>>>>> This is after: >>>>>> >>>>>> phylink_mac_ops :: mac_config() -> dsa_port_phylink_mac_config() >>>>>> -> dsa_switch_ops :: phylink_mac_config() -> mt753x_phylink_mac_config() >>>>>> -> mt753x_mac_config() >>>>>> -> mt753x_info :: mac_port_config() -> mt7530_mac_config() >>>>>> -> mt7530_setup_port5() >>>>>> -> mt7530_setup_port6() >>>>>> >>>>>> Patch 2 does not move mt7530_setup_port6() to be called from >>>>>> phylink_mac_ops :: mac_config(), it already is. There is no valid reason to >>>>>> reorder the patches. >>>>>> >>>>>> My response to Russell should've stated this instead of focusing on his >>>>>> second sentence. >>>>> >>>>> This patch moves the test for a 20MHz crystal to mt7530_setup(), >>>>> which is something that is entirely orthogonal to patch 2, which >>>>> can be done cleanly (I've just applied the patches in the original >>>>> order and then reordered them: >>>>> >>>>> 98c481f5d706 net: dsa: mt7530: do not clear config->supported_interfaces >>>>> 93c6b53b17f4 net: dsa: mt7530: correct port capabilities of MT7988 >>>>> c9c6d4c51a1d net: dsa: mt7530: simplify mt7530_setup_port6() and change to void >>>>> adfa948253e0 net: dsa: mt7530: remove pad_setup function pointer >>>>> 57e21e6c2fc0 net: dsa: mt7530: call port 6 setup from mt7530_mac_config() >>>>> 959a0f9323c8 net: dsa: mt7530: move XTAL check to mt7530_setup() >>>>> 856ab64a22ef net: dsa: mt7530: empty default case on mt7530_setup_port5() >>>>> >>>>> No problems. The end result is identical comparing the git tree at the >>>>> original "move XTAL" patch with adfa948253e0. >>>>> >>>>> Now, if we look at "net: dsa: mt7530: remove pad_setup function pointer" >>>>> we can see that yes, the pad_setup() method was called from mac_confing, >>>>> but this is the exact contents of that patch removing the callsite: >>>>> >>>>> - mt753x_pad_setup(ds, state); >>>>> >>>>> This returns an integer, which may be an error code, which is ignored. >>>>> Therefore, if the XTAL frequency check fires, and mt753x_pad_setup() >>>>> returns an error, it is ignored today. >>>>> >>>>> After "net: dsa: mt7530: call port 6 setup from mt7530_mac_config()" >>>>> the renamed pad_setup() method is now called from mac_config() thusly: >>>>> >>>>> + ret = mt7530_setup_port6(priv->ds, interface); >>>>> + if (ret) >>>>> + return ret; >>>>> >>>>> So now the error checks cause mt7530_mac_config() to return an error >>>>> which in turn causes mt753x_mac_config() to fail, and therefore >>>>> mt753x_phylink_mac_config() has different behaviour. >>>>> >>>>> So, patch 2 changes the driver behaviour in the case of a 20MHz XTAL, >>>>> which is then changed again by patch 4. >>>>> >>>>> It would be better to have only one change of behaviour by moving >>>>> patch 4 before patch 2. >>>> >>>> If the idea is to not bring any more error returns to mt753x_mac_config() >>>> because the return code is actually checked for that, I should do a bit >>>> more effort and put patch 5 before patch 2 as well, to live up to what you >>>> originally requested. >>> >>> I assume you are referring to getting rid of the default case in >>> mt7530_pad_clk_setup(). >>> >>> In patch "net: dsa: mt7530: call port 6 setup from mt7530_mac_config()" >>> where you move this to be called from mt7530_mac_config(), you add it >>> as: >>> >>> + } else if (port == 6) { >>> + ret = mt7530_setup_port6(priv->ds, interface); >>> + if (ret) >>> + return ret; >>> + } >>> >>> So it is only called for port 6. The switch within the called function >>> deals with PHY_INTERFACE_MODE_RGMII and PHY_INTERFACE_MODE_TRGMII. >>> Anything else results in the use of the default case, and thus >>> returning an error. >>> >>> Since mt7530_mac_port_get_caps() does this for port 6: >>> >>> __set_bit(PHY_INTERFACE_MODE_RGMII, >>> config->supported_interfaces); >>> __set_bit(PHY_INTERFACE_MODE_TRGMII, >>> config->supported_interfaces); >>> >>> mt7530_setup_port6() will only ever be called for these two modes, >>> which means that the default case is unreachable, thus we will never >>> execute that path, thus whether that path returns an error or not is >>> completely irrelevant. >>> >>> The only case in mt7530_setup_port6() / mt7530_pad_clk_setup() which >>> can today return an error is the XTAL check. >>> >>> Therefore, my suggestion makes complete sense, and there is no need >>> to also move patch 5. >> >> Understood. I've already submitted v4 which moves patch 5. The remaining >> benefit is that there're fewer code changes as I don't need to add an error >> return for mt7530_setup_port6() and then remove it. > > I'm pretty sure netdev has a rule _not_ to submit the next version of > a patch series if discussion about the previous is still ongoing... > but I can't find any of the netdev rules in Documentation/networking > anymore, and nothing stands out in Documentation/process... ah, > Documentation/process/maintainer-netdev.rst, and here we are: > > "Make sure you address all the feedback in your new posting. Do not post > a new > version of the code if the discussion about the previous version is > still > ongoing, unless directly instructed by a reviewer." > > Discussion was still ongoing over this point, so ideally you should > have waited instead of presenting a fait-accompli _during_ the > ongoing discussion. Thank you for bringing this to my attention. Next time I will be more careful when deciding whether the discussion was over. Arınç