From patchwork Tue Mar 5 04:39:51 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Justin Swartz X-Patchwork-Id: 13581605 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 0D954C5478C for ; Tue, 5 Mar 2024 04:41:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-Id:Date:Subject:Cc :To:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=+GrH+/QL68T6036ffBCbjTnxXxZNklctmtRIYluKbJs=; b=wxjKyIXR3PA3qI nVazUk2TnLE0exAY1ETCRuAeJE+aOn9Qri87W16xhv2iN8KQzLs0mbpMvx0EloQ0Ff9q2n+PhmC51 +OP12QaIay+sCKqPGyVBCoWcVeDn6sm+orgvdD3B2C/j1VYkFLJQ77b3daxLfnZ7FLNseOO5Lx0Gy kG9Aq8thRFtqbaLDi+bzW90pqmxA7Q0eR6zlk1BlF8zALZhmRUcLkFnsNtElvsEs8c8izQHrKL2/S tBdnwAOA/houIocaPZK4TPMkhKaJRj10RGign4qZrOig5ludGF88WXxBIoXftH71j1re1jsVF9Qjf KHEalIMtniYlF+h03eBA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rhMbv-0000000BscY-3dkD; Tue, 05 Mar 2024 04:41:03 +0000 Received: from outgoing4.flk.host-h.net ([188.40.0.90]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1rhMbq-0000000Bsb3-00LG; Tue, 05 Mar 2024 04:41:01 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=risingedge.co.za; s=xneelo; h=Content-Transfer-Encoding:MIME-Version: Message-Id:Date:Subject:Cc:To:From:reply-to:sender:bcc:in-reply-to:references :content-type; bh=m3G7uqGep2jRTiY2MUFrRQpXBp2XUJrcB1aaHLU8GHM=; b=vT1SgjPmcYN d1lFD6XiX8in9sqYFQRcj8Eoa8XyyDdh15JEydux/xq/eVD5DNWGqiDUixS6S2adw2tk62pafAA87 51h1dmdbGKc1JoPe4ytB4NSOgIXYV7sNUqfA6ZeYjsBFrKaw1Vcr1hfUfFU4Eua8b+8hhnZmBhQyv pzrdKh3GzmHc+VR7ZsPkoZyiDSn/y4/fJd0RoXu0VTv9VjMXdNLbaDxuR+umJrjSPDBAow/kl8EVb x//uqAlDcr6nFnqG7hGH+AEmS7ckGTVJn8GfZAb3YU+OCCkjoRu5Tu6NI2t+R15YUW990vC4eE2Fc 62IwLFzyd8PO+eCqW50XQ7A==; Received: from www31.flk1.host-h.net ([188.40.1.173]) by antispam1-flk1.host-h.net with esmtpsa (TLSv1.3:TLS_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1rhMbc-00HBd3-Hf; Tue, 05 Mar 2024 06:40:47 +0200 Received: from [41.144.0.96] (helo=localhost.localdomain) by www31.flk1.host-h.net with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1rhMbW-0005M8-1G; Tue, 05 Mar 2024 06:40:38 +0200 From: Justin Swartz To: =?utf-8?b?QXLEsW7DpyDDnE5BTA==?= , 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 Cc: Justin Swartz , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org Subject: [PATCH] net: dsa: mt7530: disable LEDs before reset Date: Tue, 5 Mar 2024 06:39:51 +0200 Message-Id: <20240305043952.21590-1-justin.swartz@risingedge.co.za> MIME-Version: 1.0 X-Authenticated-Sender: justin.swartz@risingedge.co.za X-Virus-Scanned: Clear X-Originating-IP: 188.40.1.173 X-SpamExperts-Domain: risingedge.co.za X-SpamExperts-Username: Authentication-Results: host-h.net; auth=pass (login) smtp.auth=@risingedge.co.za X-SpamExperts-Outgoing-Class: ham X-SpamExperts-Outgoing-Evidence: Combined (0.03) X-Recommended-Action: accept X-Filter-ID: Pt3MvcO5N4iKaDQ5O6lkdGlMVN6RH8bjRMzItlySaT8bSAwkwoC1TJJiWLFQYyDsPUtbdvnXkggZ 3YnVId/Y5jcf0yeVQAvfjHznO7+bT5wCPRB8bAzJcv2cv+UqiTTc2+CpNcmBnO4XM3Sck4bwNogU WCl1nkLBzZX0KuJ9bXiS85Z42w/+2OBolTNFbPomXFWCX8oNdggW7HE9XDTdSejrkEpbuUvwMvHx 3T+KSG//gbuP7hnUK8NQdLwsVWKIv+fXqqb3FJ1Z7kkAIev0U9CKH/oA07tJunDPm536TODb5GPR oyaaXp1VNA9dXvxV+mFktoWo3CKg4C3LDJ75vu2U4GT70q7ZqN/P49BncZ5XB7lfx9K88uL/WnJE LAEP514Y/yfAEbrTclu3OeNcbACmFr3ts0d2E6vXySsvfMaT9Bjf4etJ827HW1/sdZ81dz6BqXHU oYg+nmOeSIjjxA24TPuOyBrko5yKpcR03QEJ9DjWmjcfK/FpTD0spWG+rMYoj8CdNq4vLYsMDbt4 2oUP1Ae/eGZl2OLANHAHEjHENEhX9cq65nsXPA0MIFDIPOMDW/6+MC+5Mq5RH9OoW0W22an/ubzj InB/ImqScRfGyrhHVstPeAuxsRhUFJC4TtSvIahFt3uEpT0304dV2Yoz1SesQUA6bnjJZT6m9lal 9vikoy50DqR3hu/rL5PGAoTDzn0QdoxFeruM0Uhu+dTUSiL7T3enG3jHhaXbbkcihnVW8zB2Qi26 vkVALycwzSdeC1kd8cXa71WqOc72jXbRpMw6Agze1f399OurHEyYS7nq+EBNvgiWKNNSkdVDPqq6 +NRG0tTqWfoM12ajaPKeGaSpuwkt9kMFaoxOFH1hIqsDqiY5NFuEmlCmGLsHMs4VIrisX+dtrxYn /0jYEvj5QBAPtzfeVlNHdCJmwgf0M7fnqgzRvCMiN68tcHQey84mBB4XoB473XOJmIRPynE3O7YZ oFBs6I7QuC1BjGNT52hVLEr/9PrrMm81h6IAYzikeIJfw26MB/V1E5BP9Gv0xI1YXOxC1lZqyFpL AwQr6muMti2YanICQnMITeB2fd0UyjU/MIq3Vtx6CgQGHtezYqxGMqsKjARq8PBC4qgGsfAERwCB JFs7XjZYbJPBsmpIto2O4JO2fx1gIuNHgi11AwJSTGCrOFs22K1ZnDqAw3gLmOBPHazhChxq9nGW aSi6bFHidB1VgzDzDZn/+QEiRQv+PVjjwa+Z5RFCOMQwU3LvoOQWIGmR34v72byEdfFYVDBYJee7 gx/u82RtUwfD5ALHBf4EnQOzr8vuDU00mVfWLKEgol9rYV4JEcNP1rJoln/cD8h/RIvkzXRTCYvX WLQhlD92+1l+zHfJg1FMwntsduNBxKPaTpE5L8d4VqFy6yKUFQtzhTlGiGL9B+FvFA6U1VLNI5ac F+7LBSfmrQPvc5+YzzlWlzLxTUJwIIDSVMZhrIoAWTF5tIdhy/UIEBYDcZg+Q8UhuRLyBn1+pvlH hV6a5QjptwQBGybQyDQ2/GYwPjlMcE57ESN6G+kn87CtwPdB/10jfVNpDbYnXJdSRQj8460WHJib IxmU2pb4i4DTkMZeMiNI9JSIyUbtnrlbG4BI8o81FOo91axhCaqPShJzgHH7y4ZfQxML X-Report-Abuse-To: spam@antispamquarantine.host-h.net X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240304_204058_665455_15292282 X-CRM114-Status: GOOD ( 12.15 ) X-BeenThere: linux-arm-kernel@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-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Disable LEDs just before resetting the MT7530 to avoid situations where the ESW_P4_LED_0 and ESW_P3_LED_0 pin states may cause an unintended external crystal frequency to be selected. The HT_XTAL_FSEL (External Crystal Frequency Selection) field of HWTRAP (the Hardware Trap register) stores a 2-bit value that represents the state of the ESW_P4_LED_0 and ESW_P4_LED_0 pins (seemingly) sampled just after the MT7530 has been reset, as: ESW_P4_LED_0 ESW_P3_LED_0 Frequency ----------------------------------------- 0 1 20MHz 1 0 40MHz 1 1 25MHz The value of HT_XTAL_FSEL is bootstrapped by pulling ESW_P4_LED_0 and ESW_P3_LED_0 up or down accordingly, but: if a 40MHz crystal has been selected and the ESW_P3_LED_0 pin is high during reset, or a 20MHz crystal has been selected and the ESW_P4_LED_0 pin is high during reset, then the value of HT_XTAL_FSEL will indicate that a 25MHz crystal is present. By default, the state of the LED pins is PHY controlled to reflect the link state. To illustrate, if a board has: 5 ports with active low LED control, and HT_XTAL_FSEL bootstrapped for 40MHz. When the MT7530 is powered up without any external connection, only the LED associated with Port 3 is illuminated as ESW_P3_LED_0 is low. In this state, directly after mt7530_setup()'s reset is performed, the HWTRAP register (0x7800) reflects the intended HT_XTAL_FSEL (HWTRAP bits 10:9) of 40MHz: mt7530-mdio mdio-bus:1f: mt7530_read: 00007800 == 00007dcf >>> bin(0x7dcf >> 9 & 0b11) '0b10' But if a cable is connected to Port 3 and the link is active before mt7530_setup()'s reset takes place, then HT_XTAL_FSEL seems to be set for 25MHz: mt7530-mdio mdio-bus:1f: mt7530_read: 00007800 == 00007fcf >>> bin(0x7fcf >> 9 & 0b11) '0b11' Once HT_XTAL_FSEL reflects 25MHz, none of the ports are functional until the MT7621 (or MT7530 itself) is reset. By disabling the LED pins just before reset, the chance of an unintended HT_XTAL_FSEL value is reduced. Signed-off-by: Justin Swartz --- drivers/net/dsa/mt7530.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c index 3c1f65759..8fa113126 100644 --- a/drivers/net/dsa/mt7530.c +++ b/drivers/net/dsa/mt7530.c @@ -2238,6 +2238,12 @@ mt7530_setup(struct dsa_switch *ds) } } + /* Disable LEDs before reset to prevent the MT7530 sampling a + * potentially incorrect HT_XTAL_FSEL value. + */ + mt7530_write(priv, MT7530_LED_EN, 0); + usleep_range(1000, 1100); + /* Reset whole chip through gpio pin or memory-mapped registers for * different type of hardware */