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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 504E2C48286 for ; Sun, 4 Feb 2024 16:52:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=lTWWPxMsjq/XryQ86M+xV2rVGgxew1NiI9dJe8B9IbY=; b=SjOWo8OLH6lVpbkjvLaZjBMo/W iV6Nv+GKGyUazGbF6+tObmUWG7NkBQfMBf3x9a4q5mNrHRpSE4/vp/qXF4BQ2MUT9m/ZY6f9RbGpQ s1TJy5M8smHIKaC2DKxqssXp9vvEeBZRjgWFOT2yxQXkW/OmBCIcJSQ6la+bIOaVVehJPw65aWjuL XJ59+/im9Qbeluc/IAdtszsYBzeVIk1mbW7Dtl+Osc2dyFs9I7FRUludcyk3iFN6o7f7qUZgUkg7O tIRQDuXeTfwrwyFgee1qhVpwEckyuAalXv161iWraCMeXCFZ5x8Dfo66B1elTEXR1qAHkNJe3/Fin kaqsMR5g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rWfiy-00000001AmQ-38Ii; Sun, 04 Feb 2024 16:52:08 +0000 Received: from relay9-d.mail.gandi.net ([217.70.183.199]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1rWfiu-00000001AkI-1rdy; Sun, 04 Feb 2024 16:52:06 +0000 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 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 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240204_085204_778917_B2505F29 X-CRM114-Status: GOOD ( 32.79 ) X-BeenThere: linux-mediatek@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-mediatek" Errors-To: linux-mediatek-bounces+linux-mediatek=archiver.kernel.org@lists.infradead.org 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