Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754493Ab1BVP3P (ORCPT ); Tue, 22 Feb 2011 10:29:15 -0500 Received: from mail-fx0-f46.google.com ([209.85.161.46]:34353 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754156Ab1BVP3O convert rfc822-to-8bit (ORCPT ); Tue, 22 Feb 2011 10:29:14 -0500 MIME-Version: 1.0 X-Originating-IP: [172.22.72.244] In-Reply-To: References: <1298342392-21236-1-git-send-email-ccross@android.com> <1298342392-21236-6-git-send-email-ccross@android.com> Date: Tue, 22 Feb 2011 07:28:29 -0800 Message-ID: Subject: Re: [PATCH 5/7] ARM: tegra: timer: Enable timer and rtc clocks From: Olof Johansson To: Colin Cross Cc: linux-tegra@vger.kernel.org, konkers@android.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, mike@compulab.co.il, Russell King Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2294 Lines: 66 On Tue, Feb 22, 2011 at 12:00 AM, Colin Cross wrote: > On Mon, Feb 21, 2011 at 9:32 PM, Olof Johansson wrote: >> Hi, >> >> >> On Mon, Feb 21, 2011 at 6:39 PM, Colin Cross wrote: >>> Enable the timer and rtc clocks to prevent them being >>> turned off by the bootloader clock disabling code. >>> >>> Signed-off-by: Colin Cross >>> --- >>> ?arch/arm/mach-tegra/timer.c | ? 14 ++++++++++++-- >>> ?1 files changed, 12 insertions(+), 2 deletions(-) >>> >>> diff --git a/arch/arm/mach-tegra/timer.c b/arch/arm/mach-tegra/timer.c >>> index ffa6a68..31b4f56 100644 >>> --- a/arch/arm/mach-tegra/timer.c >>> +++ b/arch/arm/mach-tegra/timer.c >>> @@ -18,6 +18,7 @@ >>> ?*/ >>> >>> ?#include >>> +#include >>> ?#include >>> ?#include >>> ?#include >>> @@ -193,9 +194,20 @@ static struct irqaction tegra_timer_irq = { >>> >>> ?static void __init tegra_init_timer(void) >>> ?{ >>> + ? ? ? struct clk *clk; >>> ? ? ? ?unsigned long rate = clk_measure_input_freq(); >>> ? ? ? ?int ret; >>> >>> + ? ? ? clk = clk_get_sys("timer", NULL); >>> + ? ? ? BUG_ON(IS_ERR(clk)); >>> + ? ? ? clk_enable(clk); >>> + ? ? ? clk_put(clk); >>> + >>> + ? ? ? clk = clk_get_sys("rtc-tegra", NULL); >>> + ? ? ? BUG_ON(IS_ERR(clk)); >>> + ? ? ? clk_enable(clk); >>> + ? ? ? clk_put(clk); >> >> Why initialize the rtc clock here? Not all boards use it and instead >> use the rtc on the pmic. Seems wasteful to clock it unless the driver >> for it is probed and configured. > > timekeeping_suspend uses read_persistent_clock and not the RTC driver > to track time in suspend. ?The Tegra implementation of > read_persistent_clock reads from the internal RTC registers. ?Its a 32 > kHz clock, so it's power usage is negligible, and it is required on > all Tegra boards. Ah, right. A short comment to that effect near the clock enablement would be useful, but other than that: Acked-by: Olof Johansson -Olof -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/