Re: RFC: outb 0x80 in inb_p, outb_p harmful on some modern AMD64 with MCP51 laptops

Rene Herman
2007-12-10T04:19:00Z

On 09-12-07 22:25, Pavel Machek wrote:

> On Sun 2007-12-09 17:59:08, Andi Kleen wrote:

>> Yes, i guess switching to udelay at least on newer systems would
>> be a good idea. I'm not quite sure about systems without TSC though.
>
> Something like this? (Warning, will not probably even compile on
> x86-64, I do not have 64-bit compiler near me).

> static inline void native_io_delay(void)
> {
> - asm volatile("outb %%al,$0x80" : : : "memory");
> + udelay(8);
> }

Alan, did you double-check that 8 us? I tried to but I seem to not have
trustworthy documentation.

Rene.