From patchwork Thu Mar 14 10:37:21 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jose Abreu X-Patchwork-Id: 1056442 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=synopsys.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=synopsys.com header.i=@synopsys.com header.b="HnKhKe+f"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 44KlXr48X1z9s55 for ; Thu, 14 Mar 2019 21:38:04 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727385AbfCNKiA (ORCPT ); Thu, 14 Mar 2019 06:38:00 -0400 Received: from us01smtprelay-2.synopsys.com ([198.182.60.111]:34412 "EHLO smtprelay.synopsys.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726736AbfCNKh7 (ORCPT ); Thu, 14 Mar 2019 06:37:59 -0400 Received: from mailhost1.synopsys.com (mailhost1.synopsys.com [10.12.238.239]) by smtprelay.synopsys.com (Postfix) with ESMTP id 1B91010C25E5; Thu, 14 Mar 2019 03:37:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=synopsys.com; s=mail; t=1552559879; bh=zu3IXV2x1enxJJVP8oX8x9XRSshj58jSUHa/Lew54a0=; h=From:To:Cc:Subject:Date:From; b=HnKhKe+f7VYIeAwbvTLp2nHTxT2qBUoGNeDIm7geR7Gn7clApes2iAenOJ7G6/9br Rd/8Qep3e+8DybGOGsY71emxZP17cUydmWSauM8n7fRhketgP6CaJf+ALslRX04rpO pIszYCKFGM5IAYj3NkwNFZBFUI9jk10YgmiEJOVnYEMp5kuwfTmMUrpqE9BqRo+gCt QxjEwUiojwppLMKoi8yNEcHmtwh3xll2n3G15R+l1wVcW1YKRlJe1HNh6zXQOPDg/6 10uh7uNG9B0M0v/u4T53oipAPsRpM/y1pumH3fTZr/KFAhPagemn3u8vwKY29x6VLp t5udvTClsTBEw== Received: from de02dwia024.internal.synopsys.com (de02dwia024.internal.synopsys.com [10.225.19.81]) by mailhost1.synopsys.com (Postfix) with ESMTP id D07D45B41; Thu, 14 Mar 2019 03:37:25 -0700 (PDT) From: Jose Abreu To: netdev@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Jose Abreu , Andrew Lunn , Florian Fainelli , "David S. Miller" , Joao Pinto Subject: [PATCH net] net: phy: Don't assume loopback is supported Date: Thu, 14 Mar 2019 11:37:21 +0100 Message-Id: X-Mailer: git-send-email 2.7.4 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Some PHYs may not support loopback mode so we need to check if register is read-only. Fixes: f0f9b4ed2338 ("net: phy: Add phy loopback support in net phy framework") Signed-off-by: Jose Abreu Cc: Andrew Lunn Cc: Florian Fainelli Cc: "David S. Miller" Cc: Joao Pinto Reviewed-by: Florian Fainelli --- drivers/net/phy/phy_device.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c index 49fdd1ee798e..a749639d98c3 100644 --- a/drivers/net/phy/phy_device.c +++ b/drivers/net/phy/phy_device.c @@ -1918,8 +1918,24 @@ EXPORT_SYMBOL(genphy_resume); int genphy_loopback(struct phy_device *phydev, bool enable) { - return phy_modify(phydev, MII_BMCR, BMCR_LOOPBACK, - enable ? BMCR_LOOPBACK : 0); + int ret; + + ret = phy_modify(phydev, MII_BMCR, BMCR_LOOPBACK, + enable ? BMCR_LOOPBACK : 0); + if (ret < 0) + return ret; + + ret = phy_read(phydev, MII_BMCR); + if (ret < 0) + return ret; + + if (enable) { + if (ret & BMCR_LOOPBACK) + return 0; + return -EOPNOTSUPP; + } + + return 0; } EXPORT_SYMBOL(genphy_loopback);