From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0F396C433F5 for ; Thu, 4 Nov 2021 09:46:52 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id C7B1C610E7 for ; Thu, 4 Nov 2021 09:46:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org C7B1C610E7 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=sdogb8I3IgFBQ3nxa1AXqNwxjniLkepj1IFz5aJDmfc=; b=WPp1BdALdtdaqB dP/PHdtuW0LX3mcwHHtzZkMFls0P7yIO0SVlL510M382vJdqss5KgzT38uWG5+I+SETtJYAVZ8yxN zYCGlq4rAoA5TovdcaOSse9B7UVafWmhmiOlmMWxL6GKT3MbX+hy1qlB38FUpKwyTVzKQXXGUc1iQ j7cd1E96dGr89hLtgUBebHPEOXvUXa0SC6ggNdOepPNsMC7iagbXzcJgNTbyV3lrs7EB8FrF78M4Y 1aePMQ7fZlMlYB8sfl8omy+ZNdIfnHDSdz6nNtUB8+13PEHZeD8DPjiCNwseh3X+T2gA4xKrRCHN/ 7JobF7jd+uB6ncv4TCcQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1miZJD-008VIg-PU; Thu, 04 Nov 2021 09:45:23 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1miZIu-008VDi-P0 for linux-arm-kernel@lists.infradead.org; Thu, 04 Nov 2021 09:45:06 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id DDD441063; Thu, 4 Nov 2021 02:45:02 -0700 (PDT) Received: from C02TD0UTHF1T.local (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 452CC3F719; Thu, 4 Nov 2021 02:45:00 -0700 (PDT) Date: Thu, 4 Nov 2021 09:44:53 +0000 From: Mark Rutland To: Youngmin Nam Cc: Krzysztof Kozlowski , will@kernel.org, daniel.lezcano@linaro.org, tglx@linutronix.de, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, pullip.cho@samsung.com, hoony.yu@samsung.com, hajun.sung@samsung.com, myung-su.cha@samsung.com, kgene@kernel.org Subject: Re: [PATCH v2 1/2] clocksource/drivers/exynos_mct_v2: introduce Exynos MCT version 2 driver for next Exynos SoC Message-ID: <20211104094453.GA58798@C02TD0UTHF1T.local> References: <20211102001122.27516-2-youngmin.nam@samsung.com> <20211102102802.GA16545@C02TD0UTHF1T.local> <20211103000945.GA48132@perf> <83f6574b-bbab-f0c3-7198-f773c3dcfc63@canonical.com> <20211103092444.GA7013@perf> <20211103095727.GA19093@perf> <20211103100407.GA35817@C02TD0UTHF1T.local> <20211104002102.GA29618@perf> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20211104002102.GA29618@perf> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211104_024504_886555_5963E667 X-CRM114-Status: GOOD ( 20.34 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi, On Thu, Nov 04, 2021 at 09:21:02AM +0900, Youngmin Nam wrote: > On Wed, Nov 03, 2021 at 10:04:18AM +0000, Mark Rutland wrote: > > On Wed, Nov 03, 2021 at 06:57:28PM +0900, Youngmin Nam wrote: > > > On Wed, Nov 03, 2021 at 10:04:36AM +0100, Krzysztof Kozlowski wrote: > > > > On 03/11/2021 10:24, Youngmin Nam wrote: > > > > > On Wed, Nov 03, 2021 at 09:18:07AM +0100, Krzysztof Kozlowski wrote: > > > > >> On 03/11/2021 01:09, Youngmin Nam wrote: > > > > >>> On Tue, Nov 02, 2021 at 10:28:10AM +0000, Mark Rutland wrote: > > > > >>>> Previously Will asked you to try CLOCK_EVT_FEAT_PERCPU here, and to set > > > > >>>> the C3STOP flag on the arch timer via the DT when necessary, rather than > > > > >>>> trying to override the arch timer like this: > > > > >>> Yes, I believe Will's suggestion definitely will work. > > > So, how about we control timer rating value with DT ? > > > Of course the default rating value should be lower than arm arch timer's. > > > Do you agree with this? > > > > No; placing a rating value in the DT is a hack. That should *not* live > > in the DT because it's linux-internal detail and not a description of > > the HW. > > So, how do we use MCTv2 only for clock event device if there are some > limitations caused by SoC design implemention ? What limitations? Are you thinking of a known issue, or just in case there is a bug in future HW? If there is a problem, we'll need to describe that in the DT somehow, and we need to know speciifcally what that limitation is. Above you said that Will's suggestion will definitely work, which implies no such limitations. Thanks, Mark. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel