From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760829Ab3LIHQB (ORCPT ); Mon, 9 Dec 2013 02:16:01 -0500 Received: from eu1sys200aog102.obsmtp.com ([207.126.144.113]:34165 "EHLO eu1sys200aog102.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760557Ab3LIHP7 (ORCPT ); Mon, 9 Dec 2013 02:15:59 -0500 Message-ID: <52A56DE5.5010206@st.com> Date: Mon, 9 Dec 2013 08:14:45 +0100 From: Giuseppe CAVALLARO User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:17.0) Gecko/20130107 Thunderbird/17.0.2 MIME-Version: 1.0 To: Chen-Yu Tsai Cc: , Rob Herring , , , , , Srinivas Kandagatla , Maxime Ripard Subject: Re: [PATCH 01/10] net: stmmac: Enable stmmac main clock when probing hardware References: <1386350983-13281-1-git-send-email-wens@csie.org> <1386350983-13281-2-git-send-email-wens@csie.org> In-Reply-To: <1386350983-13281-2-git-send-email-wens@csie.org> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.52.138.128] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello Chen-Yu On 12/6/2013 6:29 PM, Chen-Yu Tsai wrote: > Signed-off-by: Chen-Yu Tsai > --- > > Guiseppe previously stated that the "stmmaceth" clock is the > main clock that drives the IP. The stmmac driver does not > enable this clock during the probe phase. When the driver is > built in to the kernel, this is fine because the clock maybe > on by default, or the boot loader had enabled it. > > If stmmac is built as a module, when the module is loaded, > the clock may be found unused and disabled by the kernel. the clk_prepare_enable is then called in the open. Is it not working for you? Do you mean that the stmmac_hw_init fails if you do not move the clk_get and clk_prepare_enable on top of the stmmac_dvr_probe? Peppe > > drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 24 +++++++++++++---------- > 1 file changed, 14 insertions(+), 10 deletions(-) > > diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c > index 8d4ccd3..7da71ed 100644 > --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c > +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c > @@ -2688,10 +2688,17 @@ struct stmmac_priv *stmmac_dvr_probe(struct device *device, > if ((phyaddr >= 0) && (phyaddr <= 31)) > priv->plat->phy_addr = phyaddr; > > + priv->stmmac_clk = clk_get(priv->device, STMMAC_RESOURCE_NAME); > + if (IS_ERR(priv->stmmac_clk)) { > + pr_warn("%s: warning: cannot get CSR clock\n", __func__); > + goto error_clk_get; > + } > + clk_prepare_enable(priv->stmmac_clk); > + > /* Init MAC and get the capabilities */ > ret = stmmac_hw_init(priv); > if (ret) > - goto error_free_netdev; > + goto error_hw_init; > > ndev->netdev_ops = &stmmac_netdev_ops; > > @@ -2729,12 +2736,6 @@ struct stmmac_priv *stmmac_dvr_probe(struct device *device, > goto error_netdev_register; > } > > - priv->stmmac_clk = clk_get(priv->device, STMMAC_RESOURCE_NAME); > - if (IS_ERR(priv->stmmac_clk)) { > - pr_warn("%s: warning: cannot get CSR clock\n", __func__); > - goto error_clk_get; > - } > - > /* If a specific clk_csr value is passed from the platform > * this means that the CSR Clock Range selection cannot be > * changed at run-time and it is fixed. Viceversa the driver'll try to > @@ -2759,15 +2760,18 @@ struct stmmac_priv *stmmac_dvr_probe(struct device *device, > } > } > > + clk_disable_unprepare(priv->stmmac_clk); > + > return priv; > > error_mdio_register: > - clk_put(priv->stmmac_clk); > -error_clk_get: > unregister_netdev(ndev); > error_netdev_register: > netif_napi_del(&priv->napi); > -error_free_netdev: > +error_hw_init: > + clk_disable_unprepare(priv->stmmac_clk); > + clk_put(priv->stmmac_clk); > +error_clk_get: > free_netdev(ndev); > > return NULL; >