From: Jamie Lokier <jamie@shareable.org>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: vatsa@in.ibm.com, Dave Jones <davej@redhat.com>,
lkcd-devel@lists.sourceforge.net,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
linux-ide@vger.kernel.org
Subject: Re: [PATCH] Poll-based IDE driver
Date: Thu, 9 Oct 2003 00:43:40 +0100 [thread overview]
Message-ID: <20031008234340.GB17019@mail.shareable.org> (raw)
In-Reply-To: <1065649708.10565.23.camel@dhcp23.swansea.linux.org.uk>
Alan Cox wrote:
> On Mer, 2003-10-08 at 13:14, Srivatsa Vaddagiri wrote:
> > Since my code is supposed to run when system is crashing, I would like
> > to avoid calling any function in the kernel as far as possible, since
> > the kernel and its data structures may be in a inconsistent state
> > and/or corrupted.
>
> For x86 udelay is a tiny piece of code - you could easily inline it
No, because that changes the delay. Things like whether the
instructions straddle a cache line or page boundary, or ar 4-byte or
16-byte aligned affect the timing on some x86 CPUs.
udelay must reside at a fixed memory location to get the nearest thing
to determinism that we know how to get.
-- Jamie
next prev parent reply other threads:[~2003-10-08 23:44 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-09-17 9:11 [PATCH] Poll-based IDE dump driver for LKCD Srivatsa Vaddagiri
2003-09-17 13:55 ` Alan Cox
2003-10-08 9:43 ` [PATCH] Poll-based IDE driver Srivatsa Vaddagiri
2003-10-08 11:50 ` Dave Jones
2003-10-08 12:14 ` Srivatsa Vaddagiri
2003-10-08 12:15 ` Dave Jones
2003-10-08 13:26 ` Russell King
2003-10-08 18:34 ` [lkcd-devel] " Stephen Hemminger
2003-10-08 21:48 ` Alan Cox
2003-10-08 23:43 ` Jamie Lokier [this message]
2003-10-08 16:36 ` Andre Hedrick
2003-10-08 16:48 ` Dave Jones
2003-10-09 6:57 ` Andre Hedrick
2003-10-08 21:47 ` Alan Cox
2003-10-09 7:06 ` Andre Hedrick
2003-10-13 17:41 ` PRD Table id ol
2003-10-15 20:46 ` Alan Cox
2003-10-16 11:47 ` Andre Hedrick
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