From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753861AbdBDIlY (ORCPT ); Sat, 4 Feb 2017 03:41:24 -0500 Received: from mail-wm0-f43.google.com ([74.125.82.43]:37476 "EHLO mail-wm0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753745AbdBDIlX (ORCPT ); Sat, 4 Feb 2017 03:41:23 -0500 Date: Sat, 4 Feb 2017 09:41:18 +0100 From: Daniel Lezcano To: Olof Johansson Cc: mark.rutland@arm.com, marc.zyngier@arm.com, daniel.lezcano@linaro.or, tglx@linutronix.de, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] clocksource: arm_arch_timer: print timer value at init time Message-ID: <20170204084118.GB2160@mai> References: <1482169657-15773-1-git-send-email-olof@lixom.net> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1482169657-15773-1-git-send-email-olof@lixom.net> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Dec 19, 2016 at 09:47:37AM -0800, Olof Johansson wrote: > This is useful to get an indication of how much time we spent in firmware. > > It's not guaranteed that the timer started at 0 on reset, so it's just > an approximation, and might very well be invalid on some systems. But > it's still a useful metric to have access to. Hi Olof, [ ... ] > --- a/drivers/clocksource/arm_arch_timer.c > +++ b/drivers/clocksource/arm_arch_timer.c > @@ -521,6 +521,8 @@ arch_timer_detect_rate(void __iomem *cntbase, struct device_node *np) > > static void arch_timer_banner(unsigned type) > { > + unsigned long cnt = arch_timer_read_counter(); > + arch_timer_banner() is called before arch_counter_register() where the arch_timer_read_counter() function pointer is set. Perhaps the arch_timer_banner() and arch_counter_register() should be swapped in arch_timer_common_init(). > pr_info("Architected %s%s%s timer(s) running at %lu.%02luMHz (%s%s%s).\n", > type & ARCH_CP15_TIMER ? "cp15" : "", > type == (ARCH_CP15_TIMER | ARCH_MEM_TIMER) ? " and " : "", > @@ -534,6 +536,8 @@ static void arch_timer_banner(unsigned type) > type & ARCH_MEM_TIMER ? > arch_timer_mem_use_virtual ? "virt" : "phys" : > ""); > + pr_info("Initial timer value: 0x%lx: %ld.%02lds\n", > + cnt, cnt/arch_timer_rate, (cnt/(arch_timer_rate/100)) % 100); > } > -- Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog