From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759267AbaCTQeQ (ORCPT ); Thu, 20 Mar 2014 12:34:16 -0400 Received: from mail-wg0-f42.google.com ([74.125.82.42]:45673 "EHLO mail-wg0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757428AbaCTQeN (ORCPT ); Thu, 20 Mar 2014 12:34:13 -0400 Message-ID: <532B1881.2050409@gmail.com> Date: Thu, 20 Mar 2014 17:34:09 +0100 From: Boris BREZILLON User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.3.0 MIME-Version: 1.0 To: Alexandre Belloni , Nicolas Ferre CC: Jean-Christophe Plagniol-Villard , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH] ARM: at91: panic when the mck rate is zero References: <1395332062-4967-1-git-send-email-alexandre.belloni@free-electrons.com> In-Reply-To: <1395332062-4967-1-git-send-email-alexandre.belloni@free-electrons.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Le 20/03/2014 17:14, Alexandre Belloni a écrit : > If the mck rate is zero, we'll hit the following warning: > > WARNING: CPU: 0 PID: 0 at arch/arm/mach-at91/at91sam926x_time.c:257 at91sam926x_pit_init+0x13c/0x260() > > But the kernel will continue to try booting and face a lot of divisions by zero > when trying to handle the various clocks. > > Signed-off-by: Alexandre Belloni > --- > arch/arm/mach-at91/at91sam926x_time.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/arch/arm/mach-at91/at91sam926x_time.c b/arch/arm/mach-at91/at91sam926x_time.c > index 0f04ffe9c5a8..f060f6371392 100644 > --- a/arch/arm/mach-at91/at91sam926x_time.c > +++ b/arch/arm/mach-at91/at91sam926x_time.c > @@ -250,6 +250,8 @@ void __init at91sam926x_pit_init(void) > if (IS_ERR(mck)) > panic("AT91: PIT: Unable to get mck clk\n"); > pit_rate = clk_get_rate(mck) / 16; > + if (pit_rate == 0) > + panic("AT91: PIT: can't continue, mck rate is zero\n"); You're testing pit_rate why not printing: "AT91: PIT: can't continue, *pit* rate is zero\n" Otherwise, Acked-by: Boris BREZILLON > pit_cycle = (pit_rate + HZ/2) / HZ; > WARN_ON(((pit_cycle - 1) & ~AT91_PIT_PIV) != 0); >