From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754795Ab3AOGkE (ORCPT ); Tue, 15 Jan 2013 01:40:04 -0500 Received: from devils.ext.ti.com ([198.47.26.153]:39947 "EHLO devils.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750826Ab3AOGkD (ORCPT ); Tue, 15 Jan 2013 01:40:03 -0500 Message-ID: <50F4F9EB.3010405@ti.com> Date: Tue, 15 Jan 2013 12:10:43 +0530 From: Santosh Shilimkar User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/17.0 Thunderbird/17.0 MIME-Version: 1.0 To: Mark Rutland CC: Thomas Gleixner , "nico@linaro.org" , Marc Zyngier , Will Deacon , "linux-kernel@vger.kernel.org" , "john.stultz@linaro.org" , "linux-arm-kernel@lists.infradead.org" Subject: Re: [PATCHv2 1/4] clockevents: Add generic timer broadcast receiver References: <1357742770-15028-1-git-send-email-mark.rutland@arm.com> <1357742770-15028-2-git-send-email-mark.rutland@arm.com> <20130114112951.GC7990@e106331-lin.cambridge.arm.com> <20130114121247.GD7990@e106331-lin.cambridge.arm.com> <20130114153612.GF7990@e106331-lin.cambridge.arm.com> In-Reply-To: <20130114153612.GF7990@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 On Monday 14 January 2013 09:06 PM, Mark Rutland wrote: > On Mon, Jan 14, 2013 at 02:17:26PM +0000, Thomas Gleixner wrote: >> On Mon, 14 Jan 2013, Mark Rutland wrote: >>> On Mon, Jan 14, 2013 at 11:50:55AM +0000, Thomas Gleixner wrote: >>>> On Mon, 14 Jan 2013, Mark Rutland wrote: >>>> >>>>> On Mon, Jan 14, 2013 at 11:06:31AM +0000, Thomas Gleixner wrote: >>>>>> On Wed, 9 Jan 2013, Mark Rutland wrote: >>>>>>> +#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST >>>>>>> +extern int tick_receive_broadcast(void); >>>>>>> +#else >>>>>>> +static inline int tick_receive_broadcast(void) >>>>>>> +{ >>>>>>> + return 0; >>>>>>> +} >>>>>> >>>>>> What's the inline function for? If an arch does not have broadcasting >>>>>> support it should not have a receive broadcast function call either. >>>>> >>>>> That was how this was originally structured [1], but Santosh suggested this >>>>> would break the build for !GENERIC_CLOCKEVENTS_BROADCAST [1]. It means that the >>>>> arch-specific receive path (i.e. IPI handler) doesn't have to be #ifdef'd, >>>>> which makes it less ugly. >>>> >>>> Hmm. If you want to keep the IPI around unconditionally the inline >>>> makes some sense, though the question is whether keeping an unused IPI >>>> around makes sense in the first place. I'd rather see a warning that >>>> an unexpected IPI happened than a silent inline function being called. >>> >>> How about I add a warning (e.g. "Impossible timer broadcast received.") and >>> return -EOPNOTSUPP when !GENERIC_CLOCKEVENTS_BROADCAST? >> >> You still need to do something with the return value in the arch IPI >> code, right? > > Good point. Having the stub when !CONFIG_GENERIC_CLOCKEVENTS_BROADCAST is > clearly problematic. > > I'll go with your original suggestion, removing the tick_receive_broadcast stub > for !CONFIG_GENERIC_CLOCKEVENTS_BROADCAST and I'll #idef the IPI_TIMER handler. > That way it'll fall down to the standard warning for an unexpected/unknown IPI > for arch/arm at least. > The alternative is fine by me. Regards santosh