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From: Pavel Machek <pavel@ucw.cz>
To: Felipe Contreras <felipe.contreras@gmail.com>
Cc: Russell King - ARM Linux <linux@arm.linux.org.uk>,
	Jamie Lokier <jamie@shareable.org>,
	Marek Vasut <marek.vasut@gmail.com>,
	linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] arm: remove unused code in delay.S
Date: Tue, 15 Sep 2009 12:49:20 +0200	[thread overview]
Message-ID: <20090915104919.GE19989@elf.ucw.cz> (raw)
In-Reply-To: <94a0d4530909150347h642772bvc8175109393e905f@mail.gmail.com>

On Tue 2009-09-15 13:47:01, Felipe Contreras wrote:
> On Tue, Sep 15, 2009 at 1:37 PM, Pavel Machek <pavel@ucw.cz> wrote:
> >
> >> >> > Because then you get it whenever you configure for V4 as the lowest
> >> >> > denominator CPU, which leads to the buggy behaviour on better CPUs.
> >> >> > It's far better to leave it as is and just accept that the old CPUs
> >> >> > will have longer than necessary delays.  If people really really
> >> >> > care (and there's likely to only be a small minority of them now)
> >> >> > changing the '0' to a '1' is a very simple change for them to carry
> >> >> > in their local tree.  Unlike getting the right unrolling etc.
> >> >>
> >> >> Well, they can also 'git revert' this patch. If somebody really cares
> >> >> I think they should shout now and provide a better patch, otherwise
> >> >> this one should be merged.
> >> >
> >> > On the other hand, having the code there as it currently stands is not
> >> > harmful in any way, so leaving it there is just as easy.
> >>
> >> It makes the code less understandable. I'm not sure about linux's
> >> practices, but an #if 0 generally means somebody is being lazy.
> >
> > Not in this case, as you was explained to you. You may want to add
> > explaining comment above #if 0....
> 
> Yes, but I've no idea in which situations somebody might want to
> enable that code. Old chips? Which old chips?

If you udelay() produces too long delays, as was explained in the thread. 
									Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

  reply	other threads:[~2009-09-15 10:49 UTC|newest]

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-09-13 21:05 [PATCH] arm: remove unused code in delay.S Felipe Contreras
2009-09-13 21:28 ` Marek Vasut
2009-09-13 23:00   ` Russell King - ARM Linux
2009-09-14  0:21     ` Jamie Lokier
2009-09-14  8:10       ` Russell King - ARM Linux
2009-09-14 12:58         ` Felipe Contreras
2009-09-14 14:00           ` Russell King - ARM Linux
2009-09-14 14:38             ` Felipe Contreras
2009-09-14 14:40               ` Russell King - ARM Linux
2009-09-14 15:14                 ` Felipe Contreras
2009-09-14 15:21                   ` Russell King - ARM Linux
2009-09-14 15:50                     ` Felipe Contreras
2009-09-14 16:25                       ` Marek Vasut
2009-09-14 16:54                         ` Felipe Contreras
2009-09-14 15:36                   ` Wolfram Sang
2009-09-14 16:06                     ` Felipe Contreras
2009-09-14 16:24                       ` Wolfram Sang
2009-09-15 10:37                   ` Pavel Machek
2009-09-15 10:47                     ` Felipe Contreras
2009-09-15 10:49                       ` Pavel Machek [this message]
2009-09-15 11:20                         ` Felipe Contreras
2009-09-15 12:29                     ` Steve Chen
2009-09-15 13:41                       ` Marek Vasut
2009-09-15 16:30                         ` Steve Chen
2009-09-15 18:58                           ` Felipe Contreras
2009-09-15 19:44                             ` Steve Chen
2009-09-15 20:39                               ` Marek Vasut
2009-09-15 21:04                               ` Krzysztof Halasa
2009-09-15 22:26                                 ` Steve Chen
2009-09-15 22:47                                   ` Krzysztof Halasa
2009-09-16  8:26                                     ` Steve Chen
2009-09-16 12:30                                       ` Krzysztof Halasa
2009-09-16 14:49                                         ` Steve Chen
2009-09-16 20:21                                           ` Sergei Shtylyov
2009-09-16 13:47                                 ` Russell King - ARM Linux
2009-09-17 19:32                                   ` Jamie Lokier
2009-09-17 19:41                                     ` Russell King - ARM Linux
2009-09-17 21:29                                       ` [PATCH v2] " Steve Chen
2009-09-17 21:37                                         ` Jamie Lokier
2009-09-17 22:25                                           ` Steve Chen

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