Re: [PATCH 1/2] rtc: Add UIE handling ability to rtc_class_ops

[Alexandre Belloni <alexandre.belloni@bootlin.com>]

On 30/05/2024 11:59:47+0200, Csókás Bence wrote:
> Hi!
> 
> On 5/28/24 19:56, Alexandre Belloni wrote:
> > Hello,
> > 
> > On 28/05/2024 18:13:14+0200, Csókás, Bence wrote:
> > > Currently, Update Interrupt Enable is performed by emulating
> > > it with either polling, or alarm interrupts. Some RTCs, however,
> > > can directly provide Update Interrupts.
> > > 
> > 
> > This has been removed from the kernel 13 years ago. What is your use
> > case to reintroduce it?
> 
> The rationale was in the cover letter. Currently, the RTC core uses the
> alarm system to implement UI, but this causes lost updates on PCF2129.
> However, it has built-in Update Interrupt capabilities in the form of the
> Second Interrupt, therefore we should just use that.
> 
> So my question would instead be: what was the rationale of removing it in
> the first place?

Well, you didn't answer my question which is why do you need UIE and
especially UIE from the RTC? Using the timer emulation is probably what
you want because it is in sync with your system time.


-- 
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com