From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751380AbdFDRxz (ORCPT ); Sun, 4 Jun 2017 13:53:55 -0400 Received: from hermes.aosc.io ([199.195.250.187]:58075 "EHLO hermes.aosc.io" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750944AbdFDRxu (ORCPT ); Sun, 4 Jun 2017 13:53:50 -0400 From: Icenowy Zheng To: Corentin Labbe , "David S . Miller" Cc: netdev@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-sunxi@googlegroups.com, Icenowy Zheng Subject: [PATCH] net-next: stmmac: dwmac-sun8i: ensure the EPHY is properly reseted Date: Mon, 5 Jun 2017 01:53:23 +0800 Message-Id: <20170604175323.62124-1-icenowy@aosc.io> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The EPHY may be already enabled by bootloaders which have Ethernet capability (e.g. current U-Boot). Thus it should be reseted properly before doing the enabling sequence in the dwmac-sun8i driver, otherwise the EMAC reset process may fail if no cable is plugged, and then fail the dwmac-sun8i probing. Tested on Orange Pi PC, One and Zero. All the boards fail to have dwmac-sun8i probed with "EMAC reset timeout" without cable plugged before, and with this fix they're now all able to successfully probe the EMAC without cable plugged and then use the connection after a cable is hot-plugged in. Fixes: 9f93ac8d408 ("net-next: stmmac: Add dwmac-sun8i") Signed-off-by: Icenowy Zheng --- drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c index 1a6bfe6c958f..54f93ee53ef7 100644 --- a/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c @@ -750,6 +750,11 @@ static int sun8i_dwmac_power_internal_phy(struct stmmac_priv *priv) return ret; } + /* Make sure the EPHY is properly reseted, as U-Boot may leave + * it at deasserted state, and thus it may fail to reset EMAC. + */ + reset_control_assert(gmac->rst_ephy); + ret = reset_control_deassert(gmac->rst_ephy); if (ret) { dev_err(priv->device, "Cannot deassert ephy\n"); -- 2.12.2