Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751508Ab3HBLIQ (ORCPT ); Fri, 2 Aug 2013 07:08:16 -0400 Received: from bear.ext.ti.com ([192.94.94.41]:41491 "EHLO bear.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750904Ab3HBLIO (ORCPT ); Fri, 2 Aug 2013 07:08:14 -0400 Message-ID: <51FB92F8.9020801@ti.com> Date: Fri, 2 Aug 2013 16:37:36 +0530 From: Gururaja Hebbar User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:17.0) Gecko/20130620 Thunderbird/17.0.7 MIME-Version: 1.0 To: Mark Rutland CC: Sekhar Nori , "davinci-linux-open-source@linux.davincidsp.com" , "tony@atomide.com" , "benoit.cousson@gmail.com" , "linux-kernel@vger.kernel.org" , "vaibhav.bedia@ti.com" , "benoit.cousson@linaro.org" , "linux-omap@vger.kernel.org" , "devicetree-discuss@lists.ozlabs.org" , "linux-arm-kernel@lists.infradead.org" Subject: Re: [Patch V2 4/4] ARM: dts: AM33XX: update rtc node compatibility References: <1372841225-18813-1-git-send-email-gururaja.hebbar@ti.com> <1372841225-18813-5-git-send-email-gururaja.hebbar@ti.com> <51F749B0.7020802@ti.com> <20130730145501.GA29859@e106331-lin.cambridge.arm.com> <51F7E7FA.3080702@ti.com> <20130801170537.GF8095@e106331-lin.cambridge.arm.com> In-Reply-To: <20130801170537.GF8095@e106331-lin.cambridge.arm.com> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2857 Lines: 82 On 8/1/2013 10:35 PM, Mark Rutland wrote: > On Tue, Jul 30, 2013 at 05:21:14PM +0100, Sekhar Nori wrote: >> On 7/30/2013 8:25 PM, Mark Rutland wrote: >>> On Tue, Jul 30, 2013 at 06:05:52AM +0100, Gururaja Hebbar wrote: >>>> Hi, >>>> >>>> On 7/3/2013 2:17 PM, Hebbar Gururaja wrote: >>>>> Since AM33xx RTC IP has RTC_IRQWAKEEN to support Alarm Wake-up. >>>>> >>>>> Update the rtc compatible property to "ti,am3352-rtc" to enable handling >>>>> of this feature inside rtc-omap driver. >>>> >>>> The other 2 rtc driver related patches have been pulled up. If you have >>>> no comments, can you please pull this up. >>>> >>>> Regards >>>> Gururaja >>>> >>>>> >>>>> Signed-off-by: Hebbar Gururaja >>>>> --- >>>>> :100644 100644 77aa1b0... dde180a... M arch/arm/boot/dts/am33xx.dtsi >>>>> arch/arm/boot/dts/am33xx.dtsi | 2 +- >>>>> 1 file changed, 1 insertion(+), 1 deletion(-) >>>>> >>>>> diff --git a/arch/arm/boot/dts/am33xx.dtsi b/arch/arm/boot/dts/am33xx.dtsi >>>>> index 77aa1b0..dde180a 100644 >>>>> --- a/arch/arm/boot/dts/am33xx.dtsi >>>>> +++ b/arch/arm/boot/dts/am33xx.dtsi >>>>> @@ -297,7 +297,7 @@ >>>>> }; >>>>> >>>>> rtc@44e3e000 { >>>>> - compatible = "ti,da830-rtc"; >>>>> + compatible = "ti,am3352-rtc"; >>> >>> Given that this is backwards compatible with the old binding, it would >>> be nicer to have this as: >>> >>> compatible = "ti,am3352-rtc", "ti,da830-rtc"; >>> >>> We must get into the habit of changing dts files in a >>> backwards-compatible fashion. >> >> Right, I suggested this when v1 was posted. It turns out the current >> kernel does not handle the compatilble list correctly and the string >> selected actually depends on the order in which it appears in match >> table in driver instead. >> >> I saw there were patches being discussed to fix this issue, but until >> that is fixed, we cannot really use what you (and I before) suggested. > > A temporary solution would be to list the "ti,am3352-rtc" first in the > of_match_table kernel-side. If above method is followed, then it would cause trouble on davinci platform because this rtc-omap driver is also used by Davinci platform. On davinci Plaform the driver would match with "ti,am3352-rtc" for compatible. Regards Gururaja > That way you can keep the old compatible > string in the dts compatible list, and maintain backwards compatibilty > with older kernels. > > Later if the way Linux matches compatible strings is changed, this > shouldn't break the probe order, and the of_match_table order could be > changed. > > Have I missed something? > > Thanks, > Mark. > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/