From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from relay9-d.mail.gandi.net (relay9-d.mail.gandi.net [217.70.183.199]) (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 091D6249F8; Sun, 4 Feb 2024 16:52:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.70.183.199 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707065528; cv=none; b=DafstO+qjuP4wKUHD80nMK9+paU3RTlM8BkbIbVKu3BlGkQKQGpHYc9pRS1V53FQsCLZEhGcMrvGIpeLRwbCoVKnDmpl6FHgT9KKLmm7BI5k8JmJE8aQjA6GqDPUqOlBwmGkT0mvOBfiJHk5dJU4R9v5TYayxFOnwUkPd7Ef/P4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707065528; c=relaxed/simple; bh=IuiMDzYq5uY3jd0orr9KJ2WPca7quZ/7Z8pR24y3dsw=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=tSOyFl9i5CSVd9y/Vi5238SPcUufMVkTupUJc6VgovnfEGG42g3WyzOkIubB3rza7ws+MT6Zfv5DV0foh6fWz9icHg2n6rboRhRUOJCG01WJC+TczASrCdsht/8JGPCH9Caj+7SoYQ7iQR1dwI2b1a0EAlKhCyaTcGWn+KNrZg4= 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=NJiKvJ8L; arc=none smtp.client-ip=217.70.183.199 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="NJiKvJ8L" Received: by mail.gandi.net (Postfix) with ESMTPSA id DA2EDFF802; Sun, 4 Feb 2024 16:51:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=arinc9.com; s=gm1; t=1707065516; 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=lTWWPxMsjq/XryQ86M+xV2rVGgxew1NiI9dJe8B9IbY=; b=NJiKvJ8LE15kaHibv07wnHviWNGE1RPBEYYoFDCCEyzf9inDzPe0DfZ34OAM0XvYZPRez5 OTdFT62d6A8bgNBtRxtl69olsKvC46F8FFb0y8lxmH6mRvNb2KGpzbpHpHD3y++6kYFzYX BzVBqMAY0U1DkHQS3TTl+KVO7IdWcQFYzfRijoiYmapJ7k1FMNzWT9xCrODyffiBBWXfs4 4rr6M4kR1Yk1KpuHLFKA91Nzz3PmD0wCBPSooIsM5yV7JFLxTq2sjMwGXqwyJCEdgdjogx 6tXI78G/pjduFqaOQwVKiUVxdEBU3O3FE+tbuZpoFQjtgXVKbAuUz2LtHyB0xg== Message-ID: <850064fb-59c6-4e07-962a-6a213e9e7f90@arinc9.com> Date: Sun, 4 Feb 2024 19:51:49 +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> 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 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. Arınç