From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1755219AbdKATis (ORCPT <rfc822;w@1wt.eu>);
        Wed, 1 Nov 2017 15:38:48 -0400
Received: from smtp2-g21.free.fr ([212.27.42.2]:25520 "EHLO smtp2-g21.free.fr"
        rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
        id S1755081AbdKATiq (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
        Wed, 1 Nov 2017 15:38:46 -0400
Subject: Re: [RFC] Improving udelay/ndelay on platforms where that is possible
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Alan Cox <gnomes@lxorguk.ukuu.org.uk>,
        LKML <linux-kernel@vger.kernel.org>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>,
        Steven Rostedt <rostedt@goodmis.org>, Ingo Molnar <mingo@kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Peter Zijlstra <peterz@infradead.org>,
        John Stultz <john.stultz@linaro.org>,
        Douglas Anderson <dianders@chromium.org>,
        Nicolas Pitre <nico@linaro.org>, Mark Rutland <mark.rutland@arm.com>,
        Will Deacon <will.deacon@arm.com>,
        Jonathan Austin <jonathan.austin@arm.com>,
        Arnd Bergmann <arnd@arndb.de>, Kevin Hilman <khilman@kernel.org>,
        Russell King <linux@arm.linux.org.uk>,
        Michael Turquette <mturquette@baylibre.com>,
        Stephen Boyd <sboyd@codeaurora.org>, Mason <slash.tmp@free.fr>
References: <d3f42f35-8175-58f6-78b7-3331efe64da2@sigmadesigns.com>
 <20171101175325.2557ce85@alans-desktop>
 <4b707ce0-6067-ab36-e167-1acf348d26bf@free.fr>
 <CA+55aFxxH0HE9SfUoLVqsvDKO0PfeM+vSoDmbXQv85yJcPZoPQ@mail.gmail.com>
From: Marc Gonzalez <marc_gonzalez@sigmadesigns.com>
Message-ID: <e03436d1-b140-3f29-59a6-3b1eb6bf9da4@free.fr>
Date: Wed, 1 Nov 2017 20:38:42 +0100
User-Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:52.0) Gecko/20100101
 Firefox/52.0 SeaMonkey/2.49.1
MIME-Version: 1.0
In-Reply-To: <CA+55aFxxH0HE9SfUoLVqsvDKO0PfeM+vSoDmbXQv85yJcPZoPQ@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-15
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On 01/11/2017 20:09, Linus Torvalds wrote:

> On Wed, Nov 1, 2017 at 12:03 PM, Marc Gonzalez wrote:
>
>> By default, ndelay is implemented in terms of udelay.
> 
> That's very much *NOT* the case.
> 
> Yes, there is a *fallback* for when somebody doesn't do ndelay() at
> all, but that doesn't make it the default.
> 
> It's just a "the architecture didn't implement ndelay at all, we'll
> work around it".

Yes, sorry, I wrote "default" when I meant "fallback".
(arm32 currently does not define a specific ndelay implementation.)

> So stop this idiocy already. About half of what I've seen in this
> thread has been pure garbage.

OK, I'll just send my patch, and then crawl back under my rock.

Regards.