Re: [PATCH] x86: provide a DMI based port 0x80 I/O delay override
From: Ingo Molnar
Date: Sun Dec 30 2007 - 16:33:30 EST
* Rene Herman <rene.herman@xxxxxxxxxxxx> wrote:
> On 30-12-07 21:46, Ingo Molnar wrote:
>> * Alan Cox <alan@xxxxxxxxxxxxxxxxxxx> wrote:
>>
>>>> So the current plan is to go with an io_delay=udelay default in v2.6.25,
>>>> to give this a migration window, and io_delay=none in v2.6.26 [and a
>>>> complete removal of arch/x86/kernel/io_delay.c], once the _p() uses are
>>>> fixed up. This is gradual enough to notice any regressions we care about
>>>> and also makes it nicely bisectable and gradual.
>>> You will break systems if you blindly go around disabling _p delays for
>>> ISA and LPC bus devices. The DEC Hinote laptops for example are well
>>> known for requiring the correct ISA and other keyboard controller delays.
>>> I don't expect anyone to test with a hinote or see it until it hits
>>> Debian or similar 'low resource' friendly devices.
>>
>> well, using io_delay=udelay is not 'blindly disabling'.
>
> On the other hand, the patch you just posted that makes io_delay=none
> the default _is_ blindly disabling. So that wasn't for consumption?
if you want to see the current x86.git intention then do:
git-clone git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git linux-2.6.git
cd linux-2.6.git
git-branch x86
git-checkout x86
git-pull git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86.git mm
right now the default is io_delay=udelay.
Ingo
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