Re: [DVB patch 51/54] ttpci: av7110: RC5+ remote control support

Johannes Stezenbach
2005-09-05T00:27:38Z

On Sun, Sep 04, 2005 Nish Aravamudan wrote:
> On 9/4/05, Johannes Stezenbach <js@linuxtv.org> wrote:
> > On Sun, Sep 04, 2005 Nish Aravamudan wrote:
> > > On 9/4/05, Johannes Stezenbach <js@linuxtv.org> wrote:
> > > >
> > > > -#define UP_TIMEOUT (HZ/4)
> > > > +#define UP_TIMEOUT (HZ*7/25)
> > >
> > > #define UP_TIMEOUT msecs_to_jiffies(280)
> > > #define UP_TIMEOUT (7*msecs_to_jiffies(40)
> >
> > I agree it's nicer to read, but AFAIK not required for correctness?
> > If so, then we'll fix those up in linuxtv.org CVS and submit
> > cleanup patches later.
>
> Yeah, it's correct with the three current values of HZ (100, 250 and
> 1000), but if you try a not-so-clean value (like Con did with 864, or
> something), you might run into rounding issues. msecs_to_jiffies()
> should take care of them (or will be a single point to do so
> eventually).

Well, if msecs_to_jiffies() is the new way of specifying timeouts
we'd have a lot more to fix up in our tree. But something like
a remote control key-up timeout doesn't need much precision.
Generally I see nothing wrong with HZ/4, but something like
HZ*20/1000 could be problematic with small or odd HZ values.

Agreed? Or is it desired that people generally use msecs_to_jiffies()?

Johannes