From nobody Sun Oct 5 18:19:57 2025 Received: from relay.smtp-ext.broadcom.com (relay.smtp-ext.broadcom.com [192.19.144.207]) (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 B0648156CA; Wed, 30 Jul 2025 20:25:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.19.144.207 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753907139; cv=none; b=UU0F9Z0DuO2VKZFu/mARlm13nby7LkuthNZSi1gM9iCdl/pFBsJyEE2wkh2sk0DQiw+7BAYCWw7VKh0/NI5HK29McknIG4HS6P6xSe2kag0fPs7K7jqr9JyhRtuf754Zei8cNwJGUPAOq1egrj97jF5pl1OHet+DloR/r3WJ3tU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753907139; c=relaxed/simple; bh=u12wcI6di+0QI17z5QIslTni50sbtImCXQArA8krxAg=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=QBMSRYPF4NuFScZqWtDgPheBGyzak+hfYENoC79R8hM5zgDkY+JtW4RpsCmvwmwC2MujMBAjIpfm4XQGFtN0D1D822tXqMhmOioAHikTkXgxxn5lA2iwbQbLI2xSqnLm0RtXIgqCORSwbrmpZwEGsGjFP5ZNWA94d7D6dpPnD+Y= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=broadcom.com; spf=fail smtp.mailfrom=broadcom.com; dkim=pass (1024-bit key) header.d=broadcom.com header.i=@broadcom.com header.b=cPRVf3nX; arc=none smtp.client-ip=192.19.144.207 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=broadcom.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=broadcom.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=broadcom.com header.i=@broadcom.com header.b="cPRVf3nX" Received: from mail-acc-it-01.broadcom.com (mail-acc-it-01.acc.broadcom.net [10.35.36.83]) by relay.smtp-ext.broadcom.com (Postfix) with ESMTP id 9EA54C0000F8; Wed, 30 Jul 2025 13:25:36 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 relay.smtp-ext.broadcom.com 9EA54C0000F8 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=broadcom.com; s=dkimrelay; t=1753907136; bh=u12wcI6di+0QI17z5QIslTni50sbtImCXQArA8krxAg=; h=From:To:Cc:Subject:Date:From; b=cPRVf3nXtVoUA42ddkED9sFYrxfTRFIjh/UJ5sXz1So3sABmLpgKpx1yvERSrAfJV tDZJmqw7jcYT/EQyFt2Ildm7sKmhNsR+6vz6ALZjv1YJqvmONDz1qMIN9gA51Lz1Zi jmbJqztRyjmPUzfg76c5DpCzpvAOLFRZZx9jtNLc= Received: from stbirv-lnx-1.igp.broadcom.net (stbirv-lnx-1.igp.broadcom.net [10.67.48.32]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mail-acc-it-01.broadcom.com (Postfix) with ESMTPSA id 88D024002F44; Wed, 30 Jul 2025 16:25:35 -0400 (EDT) From: Florian Fainelli To: netdev@vger.kernel.org Cc: Florian Fainelli , Doug Berger , Florian Fainelli , Broadcom internal kernel review list , Andrew Lunn , Heiner Kallweit , Russell King , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Jacob Keller , linux-kernel@vger.kernel.org (open list) Subject: [PATCH net v2] net: mdio: mdio-bcm-unimac: Correct rate fallback logic Date: Wed, 30 Jul 2025 13:25:33 -0700 Message-Id: <20250730202533.3463529-1-florian.fainelli@broadcom.com> X-Mailer: git-send-email 2.34.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" When the parent clock is a gated clock which has multiple parents, the clock provider (clk-scmi typically) might return a rate of 0 since there is not one of those particular parent clocks that should be chosen for returning a rate. Prior to ee975351cf0c ("net: mdio: mdio-bcm-unimac: Manage clock around I/O accesses"), we would not always be passing a clock reference depending upon how mdio-bcm-unimac was instantiated. In that case, we would take the fallback path where the rate is hard coded to 250MHz. Make sure that we still fallback to using a fixed rate for the divider calculation, otherwise we simply ignore the desired MDIO bus clock frequency which can prevent us from interfacing with Ethernet PHYs properly. Fixes: ee975351cf0c ("net: mdio: mdio-bcm-unimac: Manage clock around I/O a= ccesses") Signed-off-by: Florian Fainelli Reviewed-by: Andrew Lunn Reviewed-by: Simon Horman --- Changes in v2: - provide additional details as to how a parent clock can have a rate of 0 (Andrew) - incorporate Simon's feedback that an optional clock is NULL and therefore returns a rate of 0 as well drivers/net/mdio/mdio-bcm-unimac.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/net/mdio/mdio-bcm-unimac.c b/drivers/net/mdio/mdio-bcm= -unimac.c index b6e30bdf5325..7baab230008a 100644 --- a/drivers/net/mdio/mdio-bcm-unimac.c +++ b/drivers/net/mdio/mdio-bcm-unimac.c @@ -209,10 +209,9 @@ static int unimac_mdio_clk_set(struct unimac_mdio_priv= *priv) if (ret) return ret; =20 - if (!priv->clk) + rate =3D clk_get_rate(priv->clk); + if (!rate) rate =3D 250000000; - else - rate =3D clk_get_rate(priv->clk); =20 div =3D (rate / (2 * priv->clk_freq)) - 1; if (div & ~MDIO_CLK_DIV_MASK) { --=20 2.34.1