From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id BBA45221277; Wed, 13 Aug 2025 10:55:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755082556; cv=none; b=PYG2l/cUyI+JC4SAlD9pnFoslg7/07KyBVa59nPbgAWqhIIx3EyxvIWY0g5dDTfuoNiAZvsXoITVcpcaqPreJ/ZVWvscjbRntpJrgszbNuVXnoQDrPJV4RgeAmbRlELneQnFV2hF3KSty5i8TLmQqdZygIK/L1ikPZ8SUmwSeKE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755082556; c=relaxed/simple; bh=aAOWSyLd3a+OefNauWnbfg+j1F9KxO967PQXIBalszw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=gHfR+uPMMP5D1kFKvV0PXc8LLFPsCk6SEGIeWKbVKwpePpcmCH84yCrnvixpA7S+mBOsuWD6DQvMZzSSZZv+CziHIThfuEvzRM1fgt9JbGKD65FaHNwOrSuyDNWiOjA0xVhBCwOB73vY1eGd1H0N+9a21p9fwaeoR6p7Rk5/lt0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com; spf=none smtp.mailfrom=foss.arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=foss.arm.com 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 9F78512FC; Wed, 13 Aug 2025 03:55:45 -0700 (PDT) Received: from bogus (e133711.arm.com [10.1.196.55]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id BE9C03F63F; Wed, 13 Aug 2025 03:55:51 -0700 (PDT) Date: Wed, 13 Aug 2025 11:55:48 +0100 From: Sudeep Holla To: Marc Zyngier Cc: linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Sudeep Holla , Lorenzo Pieralisi , Hanjun Guo , "Rafael J. Wysocki" , Daniel Lezcano , Thomas Gleixner , Alexandru Elisei , Mark Rutland Subject: Re: [PATCH 0/4] clocksource: Add standalone MMIO ARM arch timer driver Message-ID: <20250813-macho-snobbish-alpaca-ff07fa@sudeepholla> References: <20250807160243.1970533-1-maz@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250807160243.1970533-1-maz@kernel.org> +Alexandru On Thu, Aug 07, 2025 at 05:02:39PM +0100, Marc Zyngier wrote: > For the past 10 years, both Mark and I have been lamenting about the > sorry state of the badly named "arch_timer" driver, and about the way > the MMIO part is intricately weaved into the system-register part. > > The time has finally come to have a stab at it. > > This small series simply creates a new timer driver for the MMIO arch > timer, and only that. It is an actual driver, and not some kludge that > has to run super early (that's what the per-CPU timers are for). This > allows, in turn, a pretty large cleanup of the per-CPU driver, though > there is more to come -- one thing at a time. > > As an added bonus, we get a clocksource, which the original code > didn't provide. Just in case it might be useful. The end-result is far > more readable, and about 100 lines smaller. > (Tested it on Juno R2 and FVP in both DT and ACPI boot) Tested-by: Sudeep Holla Reviewed-by: Sudeep Holla Alexandru found it useful(avoids some unexpected hang IIUC) in his setup based on bootwrapper which doesn't initialise MMIO timers. -- Regards, Sudeep