Re: [Xen-devel] [PATCH v2 06/10] hvm/hpet: comparator can only change when master clock is enabled.

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 14.04.14 at 21:50, <dslutz@xxxxxxxxxxx> wrote:
> On 04/14/14 11:07, Jan Beulich wrote:
>> As to the change - I'm not sure: The quoted description from the
>> specification cal also be read to mean that interrupt generation is
>> optional, but comparator increment will always happen. As long as
>> this can't be clarified, I'd prefer to stay with the code as is.
> 
> I think the code needs to change to match the spec.
> 
> #define timer_enabled(h, n) (timer_config(h, n) & HPET_TN_ENABLE)
> 
> vs
> 
> #define hpet_enabled(h) (h->hpet.config & HPET_CFG_ENABLE)
> 
> 
> The change uses hpet_enabled() (I.E. Overall Enable).

Correct. But do we really need this? When the HPET is globally
disabled, hpet_read_maincounter() returns a fixed value, and
hence - due to the comparators not changing either -
hpet_get_comparator() will too even without the addition. So if
at all, the change would be mostly for documentation purposes.

Jan


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel