From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759425AbcJYTJX (ORCPT ); Tue, 25 Oct 2016 15:09:23 -0400 Received: from vern.gendns.com ([206.190.152.46]:54473 "EHLO vern.gendns.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753871AbcJYTJU (ORCPT ); Tue, 25 Oct 2016 15:09:20 -0400 Subject: Re: [PATCH 1/3] usb: musb: da8xx: Call earlier clk_prepare_enable() To: Alexandre Bailon , khilman@baylibre.com, b-liu@ti.com, balbi@kernel.org References: <1477403576-11825-1-git-send-email-abailon@baylibre.com> <1477403576-11825-2-git-send-email-abailon@baylibre.com> Cc: linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org From: David Lechner Message-ID: <11bb00e0-0f76-474c-b173-5a865633fc62@lechnology.com> Date: Tue, 25 Oct 2016 14:09:20 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.3.0 MIME-Version: 1.0 In-Reply-To: <1477403576-11825-2-git-send-email-abailon@baylibre.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - vern.gendns.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - lechnology.com X-Get-Message-Sender-Via: vern.gendns.com: authenticated_id: davidmain+lechnology.com/only user confirmed/virtual account not confirmed X-Authenticated-Sender: vern.gendns.com: davidmain@lechnology.com X-Source: X-Source-Args: X-Source-Dir: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/25/2016 08:52 AM, Alexandre Bailon wrote: > The first attempt to read a register may fail because the clock may not > be enabled, and then the probe of musb driver will fail. > Call clk_prepare_enable() before the first register read. > > Signed-off-by: Alexandre Bailon > --- > drivers/usb/musb/da8xx.c | 12 ++++++------ > 1 file changed, 6 insertions(+), 6 deletions(-) > > diff --git a/drivers/usb/musb/da8xx.c b/drivers/usb/musb/da8xx.c > index 210b7e4..ec93602 100644 > --- a/drivers/usb/musb/da8xx.c > +++ b/drivers/usb/musb/da8xx.c > @@ -366,6 +366,12 @@ static int da8xx_musb_init(struct musb *musb) > > musb->mregs += DA8XX_MENTOR_CORE_OFFSET; > > + ret = clk_prepare_enable(glue->clk); > + if (ret) { > + dev_err(glue->dev, "failed to enable clock\n"); > + goto fail; You can simply return ret; here instead of goto fail; > + } > + > /* Returns zero if e.g. not clocked */ > rev = musb_readl(reg_base, DA8XX_USB_REVISION_REG); > if (!rev) > @@ -377,12 +383,6 @@ static int da8xx_musb_init(struct musb *musb) > goto fail; The unwinding on error needs to be updated so that clk_disable_unprepare() is called at this point and subsequently. Currently, all goto fail; will return without disabling the clock. > } > > - ret = clk_prepare_enable(glue->clk); > - if (ret) { > - dev_err(glue->dev, "failed to enable clock\n"); > - goto fail; > - } > - > setup_timer(&otg_workaround, otg_timer, (unsigned long)musb); > > /* Reset the controller */ >