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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 6C9C6C433F5 for ; Thu, 7 Apr 2022 07:49:47 +0000 (UTC) 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=TOYLGTI9+coNcEKz090pQwKU3XkOs+NdHdSmJZQSIZc=; b=bruTY1KDWn6m/W 3WQNnjhKPC3uUTuGG9Ikz42X1ljqpS9p7EipgxZVBwbkYlV455/kNapper39iNuXq47cG+XjLaxQ1 ZD7vGPfqKmFChhtMB4UsTFuoTBRwDg9qpK7YBd9wleX7p1071L26MF59XKunk4oYN7XRnroY2xa1K 8klUZXp/LJD38tt/79PYJ8QzY2CT/FGMXCtIsKa6l1z3lB9i9pyp9rUTjo9jukIcndoUk39ji+Wya Pi574exy9z06Y0tJhUf3iM5cljx/riIeUmfpeRdbMHigVknOKnSkDx2vhugm2WKhoxxneLoOdcr6o 4GB/D1u+qxtvGkooN6MA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1ncMsg-00A6Vi-LA; Thu, 07 Apr 2022 07:48:39 +0000 Received: from smtp1.axis.com ([195.60.68.17]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1ncMsZ-00A6Ri-4W for linux-arm-kernel@lists.infradead.org; Thu, 07 Apr 2022 07:48:32 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=axis.com; q=dns/txt; s=axis-central1; t=1649317711; x=1680853711; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=65cq+04D2t91MgXQs2FV1LSZ91INmcsG6pr3WgD2E7M=; b=oN4apwlhN93Sl3SRkUYPEZ9mCEhLh/a0yHzCfpdE5XzkaS708QoooimN 38r8jEka8oHu/w+GEC0GKlrohH5hFDMaQ/6rxVYjEHO0sx7H6DOQb3XTz KS3hTKMpugHDqNPTvGUgYVSv5u4JIQg5Ca896pMSPM0v08tbJUwqESHMF 0aMuReYyRl//HxzCj7FhCAfJ/1Hb28fO23dum5AJQ1KM63tsNkYNdcI6R Wfc9GGc1YSHR8p2OSWSQL6BdiAZJHf9tMgc/07sFeOmWVM6jbDdrgVXqE iAhpyJVk7rjHws448cBlZR7nhwkC5ZtYGVHE+EHupIPG/FNfYmRjzg55P w==; Date: Thu, 7 Apr 2022 09:48:29 +0200 From: Vincent Whitchurch To: Marek Szyprowski CC: "devicetree@vger.kernel.org" , "linux-samsung-soc@vger.kernel.org" , "daniel.lezcano@linaro.org" , "linux-kernel@vger.kernel.org" , "robh+dt@kernel.org" , kernel , "alim.akhtar@samsung.com" , "tglx@linutronix.de" , "linux-arm-kernel@lists.infradead.org" , Subject: Re: [PATCH v2 3/4] clocksource/drivers/exynos_mct: Support local-timer-index property Message-ID: <20220407074829.GA31389@axis.com> References: <20220308142410.3193729-1-vincent.whitchurch@axis.com> <20220308142410.3193729-4-vincent.whitchurch@axis.com> <226dcb1b-d141-f0d3-68c4-11d2466ca571@canonical.com> <20220311113543.GA17877@axis.com> <69be9f88-b69b-c149-4387-c5002219bf0a@canonical.com> <20220330082137.GA21079@axis.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20220330082137.GA21079@axis.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220407_004831_577405_0C917557 X-CRM114-Status: GOOD ( 18.91 ) 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 On Wed, Mar 30, 2022 at 10:21:37AM +0200, Vincent Whitchurch wrote: > On Mon, Mar 21, 2022 at 09:00:08AM +0100, Marek Szyprowski wrote: > > Right, I've played a bit with MCT on some older Exynos SoCs (ARM 32bit > > based and even Exynos5433) and it looked that none of it enabled MCT FRC > > timer in their proprietary firmware. I've even proposed a patch for this > > once ([1]), but such approach has been rejected. I think that calling > > exynos4_mct_frc_start() unconditionally won't hurt. > > Thank you for looking into this. The proposal was however not to avoid > changing when exynos4_mct_frc_start() is called, but to instead skip the > write to the Timer Enable bit of the G_TCON register if it is already > set, like in the below patch. (This is needed to avoid races when the > FRC is shared between CPUs in an AMP configuration, since TCON can be > modified for other reasons from the CPU which is using the global > comparator.) > > If I understand your comment correctly, such a change should not cause > any difference at least on the platforms you looked at since there > MCT_G_TCON_START will not have been set at startup. I needed the frc-shared property anyway to prevent registration of the clock events so I followed Krzysztof's suggestion of doing this conditionally and also clearing the resume callback. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel