Re: [discuss] Re: 2.6.15-rc5-mm1 (x86_64-hpet-overflow.patch breaks resume from disk)

Jan Beulich
2005-12-09T10:56:44Z

>> >Also I think vgettimeofday doesn't handle 64bit HPET correctly
>> >yet. Also why does it not use hpet_readq?
>>
>> For the simple reason that there is no way to know whether the
entire
>> interconnect from CPU to HPET is (at least) 64 bits wide. At least
>> theoretically implementations are permitted to use 32-bit
components;
>> the HPET spec specifically warns about that.
>
>Doesn't that refer to the CPUs ?

No, all bus components and other chips between CPU and the implementing
chip (including the latter) must have 64-bit data paths and guarantee
not to break up 64-bit reads into pairs of 32-bit ones. Actually, it's
the other way around - since most modern 32-but x86 CPUs have (as far as
I know) 64-bit data busses, it is normally not the CPU that restricts
accesses to 32 bits.

Jan