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 74F4CC54791 for ; Wed, 13 Mar 2024 14:51:18 +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=AaM381CaRCKupfxn5pAdYs1OJs8ihezxig7NOUyoXBs=; b=ZPNAfL1n+OwRoI jfUh0SH0Wa5ynzz9zOgCD9CiC+pKIIyuSq5h5bnYoAxcepDRYraK5suzIRCp2Ptzc5Pbei56DwRKI x0zLTc/v8cbleR6XHvlUZP47G4yWjA1MuSwW23oIYHoQaObPJh/bHRBze3lAOr1ffvKXMJ9f87GgX w9GuPjD00JMgk2ZhDWJWUKNwnX8pIkT8AyCGlCgW004KEte0Fbts5L6Fpt6frz21BlLPpVUi33dKq qKDnDtz67EpBxXdY5t+fA/8zPQpr2kC0VIPR4rHX8qxeSt4KuhwpjJM4xJrhWSjzo7V313ORKly0+ ouJH2hdD/LZwYd+Y/EVg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rkPwd-0000000AUL1-2PE4; Wed, 13 Mar 2024 14:51:03 +0000 Received: from relay5-d.mail.gandi.net ([2001:4b98:dc4:8::225]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1rkPwa-0000000AUJe-1YCY for linux-arm-kernel@lists.infradead.org; Wed, 13 Mar 2024 14:51:02 +0000 Received: by mail.gandi.net (Postfix) with ESMTPSA id 31F8F1C0009; Wed, 13 Mar 2024 14:50:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1710341457; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=8VJkHw9Sd5alOnv5C50Y3H8ffoBOxoKu755mmz9UUEI=; b=NanRpLdQ1MKcQhvI41Tc50fWxjFE6Ck2VgQfOtWkPRHoqBld3vHI/Df6Mt37+cqK3PfJSa 4zJ/kPmXzvsfOvjrZ7OupGuHiG0S78UA2iKK9Wkc+DUWGnjxUpWckZ2Rk6q+KWUEGJPVef lSW/qwmCFjWiBShrjbjamuTxCqNpaAf1fdyeVwCJyZ0V1UBbzHAiWDEWCscClK4Le61Om/ A38TN5xhY+0WJIBKLCkD7KKFIo7jHhQIpy36lWks5LyFUG0yAJCtwQx2RhVnRXtKXxm64X iQT301CSo1jomtMpFfVDud/Tppvvx2d9Y8bbHkN0yTPFMwJo1e8Yaj9WXKoflg== Date: Wed, 13 Mar 2024 15:50:54 +0100 From: Alexandre Belloni To: David Woodhouse Cc: Peter Hilber , linux-kernel@vger.kernel.org, virtualization@lists.linux.dev, virtio-dev@lists.oasis-open.org, linux-arm-kernel@lists.infradead.org, linux-rtc@vger.kernel.org, "virtio-comment@lists.oasis-open.org" , "Christopher S. Hall" , Jason Wang , John Stultz , "Michael S. Tsirkin" , netdev@vger.kernel.org, Richard Cochran , Stephen Boyd , Thomas Gleixner , Xuan Zhuo , Marc Zyngier , Mark Rutland , Daniel Lezcano , Alessandro Zummo , "Ridoux, Julien" Subject: Re: [RFC PATCH v3 0/7] Add virtio_rtc module and related changes Message-ID: <202403131450547f373268@mail.local> References: <0e21e3e2be26acd70b5575b9932b3a911c9fe721.camel@infradead.org> <204c6339-e80d-4a98-8d07-a11eeb729497@opensynergy.com> <667c8d944ce9ea5c570b82b1858a70cc67b2f3e4.camel@infradead.org> <57704b2658e643fce30468dffd8c1477607f59fb.camel@infradead.org> <202403131118010e7ed5bf@mail.local> <20240313125813ec78d5a9@mail.local> <96be7312f7bddaf06c690e082a8028fa8b511deb.camel@infradead.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <96be7312f7bddaf06c690e082a8028fa8b511deb.camel@infradead.org> X-GND-Sasl: alexandre.belloni@bootlin.com X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240313_075100_724830_66F07E92 X-CRM114-Status: GOOD ( 15.78 ) 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 13/03/2024 14:06:42+0000, David Woodhouse wrote: > If you're asking why patch 7/7 in Peter's series exists to expose the > virtio clock through RTC, and you're not particularly interested in the > first six, I suppose that's a fair question. As is the question of "why > is it called virtio_rtc not virtio_ptp?". > Exactly my question, thanks :) > But let me turn it around: if the kernel has access to this virtio > device and *not* any other RTC, why *wouldn't* the kernel use the time > from it? The fact that it can optionally *also* provide paired readings > with the CPU counter doesn't actually *hurt* for the RTC use case, does > it? As long as it doesn't behave differently from the other RTC, I'm fine with this. This is important because I don't want to carry any special infrastructure for this driver or to have to special case this driver later on because it is incompatible with some evolution of the subsystem. -- Alexandre Belloni, co-owner and COO, Bootlin Embedded Linux and Kernel engineering https://bootlin.com _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel