Messages in this thread |  | | Date | Sat, 15 Dec 2007 14:27:25 +0100 | | From | Ingo Molnar <> | | Subject | Re: [PATCH] x86_64: fix problems due to use of "outb" to port 80 on some AMD64x2 laptops, etc. |
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* Rene Herman <rene.herman@gmail.com> wrote:
> The issue is -- how do you safely replace the outb pre-loops_per_jiffy > calibration? I'm currently running with the attached hack (not > submitted, only for 32-bit and discussion) the idea of which might be > the best we can do?
how about doing a known-NOP chipset cycle? For example:
inb(PIC_SLAVE_IMR)
? I.e. instead of trying to find an unused port, lets try to find a known-used platform register that has no side-effects if read. Use it unconditionally during early bootup and change it to an udelay after calibration. (or use it after early bootup too if a boot parameter has been specified) Or something like this.
Ingo
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