Re: [coreboot] [PATCH 2/4] Enable TSC calibration with timer2 by default.

[Patrick Georgi]

Am 08.09.2010 02:23, schrieb Kevin O'Connor:
> As an aside, I'm not sure of the value of TSC based delays if
> inb(0x80) is used to time it.  If the code assumes inb(0x80) is 1
> usecond, I'd think it could as easily use UDELAY_IO instead.  I guess
> we'll need to see if any boards need the new TSC_CALIBRATE_WITH_IO
> setting.

As I understand it, TSC from IO is still more reliable than UDELAY_IO as
it uses a _large_ sampling of IO accesses to average out timing.

But I'm not sure how much difference that really makes.

Patrick