Re: [Qemu-devel] [PATCH v2 2/4] RTC:Add RTC update-ended interrupt logic

[Zhang, Yang Z]

> -----Original Message-----
> From: Paolo Bonzini [mailto:address@hidden On Behalf Of Paolo
> Bonzini
> Sent: Monday, February 20, 2012 3:38 PM
> To: Zhang, Yang Z
> Cc: address@hidden; Jan Kiszka; address@hidden;
> address@hidden; Marcelo Tosatti
> Subject: Re: [PATCH v2 2/4] RTC:Add RTC update-ended interrupt logic
> 
> On 02/20/2012 01:25 AM, Zhang, Yang Z wrote:
> > Use timer to emulate RTC update-ended interrupt. The timer is enabled
> > only when UIE is setting.
> 
> The timer needs to be enabled when UF is clear, not when UIE is set.  If UIE 
> is
> set but the update interrupt is masked you do not need to do anything; on the
> other hand you need to update UF in case the guest is observing interrupts 
> with
> polling.
Good point.

best regards
yang