From: Arnd Bergmann <arnd@arndb.de>
To: Ley Foon Tan <lftan@altera.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Linux-Arch <linux-arch@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org>,
Chung-Lin Tang <cltang@codesourcery.com>
Subject: Re: [PATCH v5 21/29] nios2: Time keeping
Date: Tue, 28 Oct 2014 10:23:37 +0100 [thread overview]
Message-ID: <1806277.3CF96bVORX@wuerfel> (raw)
In-Reply-To: <CAFiDJ5_zsyQ92W4iYG2Ria12TKpkFa8Au5noos1=gtq6_aPyjg@mail.gmail.com>
On Tuesday 28 October 2014 10:46:29 Ley Foon Tan wrote:
> On Sun, Oct 26, 2014 at 5:10 AM, Thomas Gleixner <tglx@linutronix.de> 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
next prev parent reply other threads:[~2014-10-28 9:23 UTC|newest]
Thread overview: 80+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-24 8:24 [PATCH v5 00/29] nios2 Linux kernel port Ley Foon Tan
2014-10-24 8:24 ` Ley Foon Tan
2014-10-24 8:24 ` [PATCH v5 01/29] asm-generic: add generic futex for !CONFIG_SMP Ley Foon Tan
2014-10-24 8:24 ` Ley Foon Tan
2014-10-25 20:50 ` Thomas Gleixner
2014-10-24 8:24 ` [PATCH v5 02/29] nios2: Assembly macros and definitions Ley Foon Tan
2014-10-24 8:24 ` Ley Foon Tan
2014-10-24 8:24 ` [PATCH v5 03/29] nios2: Kernel booting and initialization Ley Foon Tan
2014-10-24 8:24 ` Ley Foon Tan
2014-10-24 8:24 ` [PATCH v5 04/29] nios2: Exception handling Ley Foon Tan
2014-10-24 8:24 ` Ley Foon Tan
2014-10-24 9:15 ` Geert Uytterhoeven
2014-10-27 9:43 ` Ley Foon Tan
2014-10-24 8:24 ` [PATCH v5 05/29] nios2: Traps exception handling Ley Foon Tan
2014-10-24 8:24 ` Ley Foon Tan
2014-10-24 8:24 ` [PATCH v5 06/29] nios2: Memory management Ley Foon Tan
2014-10-24 8:24 ` Ley Foon Tan
2014-10-24 8:24 ` [PATCH v5 07/29] nios2: I/O Mapping Ley Foon Tan
2014-10-24 8:24 ` Ley Foon Tan
2014-10-28 13:30 ` Arnd Bergmann
2014-10-29 7:00 ` Ley Foon Tan
2014-10-24 8:24 ` [PATCH v5 08/29] nios2: MMU Fault handling Ley Foon Tan
2014-10-24 8:24 ` Ley Foon Tan
2014-10-24 8:24 ` [PATCH v5 09/29] nios2: Page table management Ley Foon Tan
2014-10-24 8:24 ` Ley Foon Tan
2014-10-24 8:24 ` [PATCH v5 10/29] nios2: Process management Ley Foon Tan
2014-10-24 8:24 ` Ley Foon Tan
2014-10-24 8:24 ` [PATCH v5 11/29] nios2: Cache handling Ley Foon Tan
2014-10-24 8:24 ` Ley Foon Tan
2014-10-24 8:24 ` [PATCH v5 12/29] nios2: TLB handling Ley Foon Tan
2014-10-24 8:24 ` Ley Foon Tan
2014-10-24 8:24 ` [PATCH v5 13/29] nios2: Interrupt handling Ley Foon Tan
2014-10-24 8:24 ` Ley Foon Tan
2014-10-24 8:24 ` [PATCH v5 14/29] nios2: DMA mapping API Ley Foon Tan
2014-10-24 8:24 ` Ley Foon Tan
2014-10-24 8:24 ` [PATCH v5 15/29] Add ELF machine define for Nios2 Ley Foon Tan
2014-10-24 8:24 ` Ley Foon Tan
2014-10-24 8:24 ` [PATCH v5 16/29] nios2: ELF definitions Ley Foon Tan
2014-10-24 8:24 ` Ley Foon Tan
2014-10-24 8:24 ` [PATCH v5 17/29] nios2: System calls handling Ley Foon Tan
2014-10-24 8:24 ` Ley Foon Tan
2014-10-24 8:24 ` [PATCH v5 18/29] nios2: Signal handling support Ley Foon Tan
2014-10-24 8:24 ` Ley Foon Tan
2014-10-24 8:24 ` [PATCH v5 19/29] nios2: Library functions Ley Foon Tan
2014-10-24 8:24 ` Ley Foon Tan
2014-10-24 8:24 ` [PATCH v5 20/29] nios2: Device tree support Ley Foon Tan
2014-10-24 8:24 ` Ley Foon Tan
2014-10-24 8:24 ` [PATCH v5 21/29] nios2: Time keeping Ley Foon Tan
2014-10-24 8:24 ` Ley Foon Tan
2014-10-25 21:10 ` Thomas Gleixner
2014-10-28 2:46 ` Ley Foon Tan
2014-10-28 9:23 ` Arnd Bergmann [this message]
2014-10-28 10:43 ` Ley Foon Tan
2014-10-28 13:39 ` Arnd Bergmann
2014-10-29 7:36 ` Ley Foon Tan
2014-10-28 15:15 ` Thomas Gleixner
2014-10-30 9:03 ` Ley Foon Tan
2014-10-24 8:24 ` [PATCH v5 22/29] nios2: Cpuinfo handling Ley Foon Tan
2014-10-24 8:24 ` Ley Foon Tan
2014-10-24 8:24 ` [PATCH v5 23/29] nios2: Miscellaneous header files Ley Foon Tan
2014-10-24 8:24 ` Ley Foon Tan
2014-10-24 8:24 ` [PATCH v5 24/29] nios2: Nios2 registers Ley Foon Tan
2014-10-24 8:24 ` Ley Foon Tan
2014-10-24 8:24 ` [PATCH v5 25/29] nios2: Module support Ley Foon Tan
2014-10-24 8:24 ` Ley Foon Tan
2014-10-24 8:24 ` [PATCH v5 26/29] nios2: ptrace support Ley Foon Tan
2014-10-24 8:24 ` Ley Foon Tan
2014-10-24 8:24 ` [PATCH v5 27/29] MAINTAINERS: Add nios2 maintainer Ley Foon Tan
2014-10-24 8:24 ` Ley Foon Tan
2014-10-24 8:24 ` [PATCH v5 28/29] Documentation: Add documentation for Nios2 architecture Ley Foon Tan
2014-10-24 8:24 ` Ley Foon Tan
2014-10-24 8:24 ` [PATCH v5 29/29] nios2: Build infrastructure Ley Foon Tan
2014-10-24 8:24 ` Ley Foon Tan
2014-10-24 9:10 ` Geert Uytterhoeven
2014-10-27 9:44 ` Ley Foon Tan
2014-10-28 13:38 ` Arnd Bergmann
2014-10-30 10:44 ` Ley Foon Tan
2014-10-30 10:49 ` Thomas Gleixner
2014-10-30 11:33 ` Arnd Bergmann
2014-10-31 1:28 ` Ley Foon Tan
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