From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756154Ab3CLXIr (ORCPT ); Tue, 12 Mar 2013 19:08:47 -0400 Received: from mho-03-ewr.mailhop.org ([204.13.248.66]:22912 "EHLO mho-01-ewr.mailhop.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755895Ab3CLXIp (ORCPT ); Tue, 12 Mar 2013 19:08:45 -0400 X-Mail-Handler: Dyn Standard SMTP by Dyn X-Originating-IP: 72.84.113.162 X-Report-Abuse-To: abuse@dyndns.com (see http://www.dyndns.com/services/sendlabs/outbound_abuse.html for abuse reporting information) X-MHO-User: U2FsdGVkX19YRMmdUiqF9TVMV6PBFpctNKpCiu4smpU= Date: Tue, 12 Mar 2013 19:08:43 -0400 From: Jason Cooper To: Greg Kroah-Hartman Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, Simon Baatz , Andrew Lunn Subject: Re: [ 33/40] rtc: rtc-mv: Add support for clk to avoid lockups Message-ID: <20130312230843.GK12700@titan.lakedaemon.net> References: <20130312223211.492954675@linuxfoundation.org> <20130312223214.995095830@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130312223214.995095830@linuxfoundation.org> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Greg, On Tue, Mar 12, 2013 at 03:43:54PM -0700, Greg Kroah-Hartman wrote: > 3.4-stable review patch. If anyone has any objections, please let me know. > > ------------------ > > From: Andrew Lunn > > commit 89c58c198b252f2bc20657fdd72a2aea788c435c upstream. > > The Marvell RTC on Kirkwood makes use of the runit clock. Ensure the > driver clk_prepare_enable() this clock, otherwise there is a danger > the SoC will lockup when accessing RTC registers with the clock > disabled. > > Reported-by: Simon Baatz > Signed-off-by: Andrew Lunn > Tested-by: Simon Baatz > Signed-off-by: Jason Cooper > Signed-off-by: Greg Kroah-Hartman > > --- > arch/arm/boot/dts/kirkwood.dtsi | 1 + > drivers/rtc/rtc-mv.c | 28 ++++++++++++++++++++++++---- > 2 files changed, 25 insertions(+), 4 deletions(-) Please drop from 3.4-stable. devm_clk_get() wasn't available. thx, Jason. > > --- a/arch/arm/boot/dts/kirkwood.dtsi > +++ b/arch/arm/boot/dts/kirkwood.dtsi > @@ -31,6 +31,7 @@ > compatible = "mrvl,kirkwood-rtc", "mrvl,orion-rtc"; > reg = <0x10300 0x20>; > interrupts = <53>; > + clocks = <&gate_clk 7>; > }; > }; > }; > --- a/drivers/rtc/rtc-mv.c > +++ b/drivers/rtc/rtc-mv.c > @@ -14,6 +14,7 @@ > #include > #include > #include > +#include > #include > #include > > @@ -41,6 +42,7 @@ struct rtc_plat_data { > struct rtc_device *rtc; > void __iomem *ioaddr; > int irq; > + struct clk *clk; > }; > > static int mv_rtc_set_time(struct device *dev, struct rtc_time *tm) > @@ -221,6 +223,7 @@ static int __devinit mv_rtc_probe(struct > struct rtc_plat_data *pdata; > resource_size_t size; > u32 rtc_time; > + int ret = 0; > > res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > if (!res) > @@ -239,11 +242,17 @@ static int __devinit mv_rtc_probe(struct > if (!pdata->ioaddr) > return -ENOMEM; > > + pdata->clk = devm_clk_get(&pdev->dev, NULL); > + /* Not all SoCs require a clock.*/ > + if (!IS_ERR(pdata->clk)) > + clk_prepare_enable(pdata->clk); > + > /* make sure the 24 hours mode is enabled */ > rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS); > if (rtc_time & RTC_HOURS_12H_MODE) { > dev_err(&pdev->dev, "24 Hours mode not supported.\n"); > - return -EINVAL; > + ret = -EINVAL; > + goto out; > } > > /* make sure it is actually functional */ > @@ -252,7 +261,8 @@ static int __devinit mv_rtc_probe(struct > rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS); > if (rtc_time == 0x01000000) { > dev_err(&pdev->dev, "internal RTC not ticking\n"); > - return -ENODEV; > + ret = -ENODEV; > + goto out; > } > } > > @@ -268,8 +278,10 @@ static int __devinit mv_rtc_probe(struct > } else > pdata->rtc = rtc_device_register(pdev->name, &pdev->dev, > &mv_rtc_ops, THIS_MODULE); > - if (IS_ERR(pdata->rtc)) > - return PTR_ERR(pdata->rtc); > + if (IS_ERR(pdata->rtc)) { > + ret = PTR_ERR(pdata->rtc); > + goto out; > + } > > if (pdata->irq >= 0) { > writel(0, pdata->ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS); > @@ -282,6 +294,11 @@ static int __devinit mv_rtc_probe(struct > } > > return 0; > +out: > + if (!IS_ERR(pdata->clk)) > + clk_disable_unprepare(pdata->clk); > + > + return ret; > } > > static int __exit mv_rtc_remove(struct platform_device *pdev) > @@ -292,6 +309,9 @@ static int __exit mv_rtc_remove(struct p > device_init_wakeup(&pdev->dev, 0); > > rtc_device_unregister(pdata->rtc); > + if (!IS_ERR(pdata->clk)) > + clk_disable_unprepare(pdata->clk); > + > return 0; > } > > >