Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932109AbaJ1JXp (ORCPT ); Tue, 28 Oct 2014 05:23:45 -0400 Received: from mout.kundenserver.de ([212.227.126.187]:58683 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750824AbaJ1JXn (ORCPT ); Tue, 28 Oct 2014 05:23:43 -0400 From: Arnd Bergmann To: Ley Foon Tan Cc: Thomas Gleixner , Linux-Arch , "linux-kernel@vger.kernel.org" , "linux-doc@vger.kernel.org" , Chung-Lin Tang Subject: Re: [PATCH v5 21/29] nios2: Time keeping Date: Tue, 28 Oct 2014 10:23:37 +0100 Message-ID: <1806277.3CF96bVORX@wuerfel> User-Agent: KMail/4.11.5 (Linux/3.16.0-10-generic; KDE/4.11.5; x86_64; ; ) In-Reply-To: References: <1414139071-3818-1-git-send-email-lftan@altera.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-Provags-ID: V02:K0:3k3yyADQhQ+iIwj+fTTQum26UyUdoyCjEDG6kX7ofMl SgV7GKWeCVU0pQBrYa+VMBlZ0IcVjDrz/7kOLgkJIOC4Cl6QLE OyVEzQXVM9pgcU+tR8g1D4C36C7mU2KdyeYMaDLRk9NWmUgUN6 h1QC/QXL9s70+KIiKXaMHHBQx1cL/HGtnecG3CgmT1IAOnVtTw eWyHH5a64dM2dSg9Gr7GNipYyFEyQf//GzeqrqzPKeTtN5Y262 a/A1l50tchpUnsnm3ccTu+YGZsLScA/2u26aXRxNZLc94XrC7B fV7J4vakn6weVNwUR0OL7rYLiw5XP8Jz7xmnJ16zHQGKQLoYNg GJLg4tJ3qwz9+8YfIhhU= X-UI-Out-Filterresults: notjunk:1; Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tuesday 28 October 2014 10:46:29 Ley Foon Tan wrote: > On Sun, Oct 26, 2014 at 5:10 AM, Thomas Gleixner wrote: > > On Fri, 24 Oct 2014, Ley Foon Tan wrote: > >> +#ifndef _ASM_NIOS2_TIMEX_H > >> +#define _ASM_NIOS2_TIMEX_H > >> + > >> +typedef unsigned long cycles_t; > >> + > >> +extern cycles_t get_cycles(void); > >> + > >> +#define ARCH_HAS_READ_CURRENT_TIMER > > > > Why does NIOS need that? Does it have a hardware implementation > > dependent clock frequency which needs to be calibrated at boot time? > This is suggestion from Arnd to use read_current_timer instead of using > expensive delay loop calibration during boot. My mistake, sorry. I think the right way is to define calibrate_delay_is_known() rather than read_current_timer(), I was getting confused by the ARM implementation that does both. Arnd -- 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/