Messages in this thread Patch in this message | | | Date | Mon, 17 Dec 2007 15:39:00 +0100 | From | Ingo Molnar <> | Subject | Re: [PATCH] x86: provide a DMI based port 0x80 I/O delay override. |
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* David P. Reed <dpreed@reed.com> wrote:
> Rene Herman wrote: >> No, most definitely not. Having the user select udelay or none through the >> kernel config and then the kernel deciding "ah, you know what, I'll know >> better and use port access anyway" is _utterly_ broken behaviour. Software >> needs to listen to its master. > > When acting as an ordinary user, the .config is beyond my control > (except on Gentoo). It is in control of the distro (Fedora, Ubuntu, > ... but perhaps not Gentoo). I think the distro guys want a default > behavior that is set in .config, with quirk overrides being done when > needed. And of course the user in his/her boot params gets the final > say.
yeah, that's exactly the thinking. Distros basically set general policy, but a quirk is (almost) always specific and correct enough to override that. We could perhaps refine this by directing the quirk to only be applied if the current type is 0x80 - because in that case we know that it's definitely not going to work. I.e. something like the small patch below?
Ingo
--- arch/x86/kernel/io_delay.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
Index: linux-x86.q/arch/x86/kernel/io_delay.c =================================================================== --- linux-x86.q.orig/arch/x86/kernel/io_delay.c +++ linux-x86.q/arch/x86/kernel/io_delay.c @@ -47,8 +47,11 @@ EXPORT_SYMBOL(native_io_delay); static int __init dmi_io_delay_0xed_port(const struct dmi_system_id *id) { - printk(KERN_NOTICE "%s: using 0xed I/O delay port\n", id->ident); - io_delay_type = CONFIG_IO_DELAY_TYPE_0XED; + if (io_delay_type == CONFIG_IO_DELAY_TYPE_0X80) { + printk(KERN_NOTICE "%s: using 0xed I/O delay port\n", + id->ident); + io_delay_type = CONFIG_IO_DELAY_TYPE_0XED; + } return 0; }
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