On Tue, May 11, 2010 at 07:53:23AM -0700, Kevin Hilman wrote: > Dmitry Torokhov <dmitry.torok...@gmail.com> writes: > > > On Tue, May 11, 2010 at 12:03:44AM -0500, Arce, Abraham wrote: > >> Hi again Dmitry, > >> > >> > No worries, although at first I was surprised that Trilok spoke exactly > >> > the same words I did ;) > >> > > >> > >> :) > >> > >> > > > > > + > >> > > > > > +/* Interrupt thread handler thread */ > >> > > > > > + > >> > > > > > +static irqreturn_t omap_keypad_threaded(int irq, void *dev_id) > >> > > > > > +{ > >> > > > > > >> > > > > Why is iti threaded? I fo not see anything that will sleep. > >> > > > >> > > > >> > > It was implemented based on previous comments... > >> > > > >> > > >> > Would you point me to that comment? Like I said, I do not see anything > >> > that would possibly sleep in this routine so you don't need to use > >> > threaded interrupt. > >> > >> http://www.mail-archive.com/linux-omap@vger.kernel.org/msg26352.html > >> > > > > Thanks. > > > > I think Kevin meant "use theaded IRQ, wherever possible" [if we need > > to sleep in interrupt handler]. > > Actually, even interrupts that don't sleep can use threaded IRQs. I > prefer to see threaded IRQs wherever possible. Especially since we're > moving towards a world where all interrupts are run with interrupts > disabled, using threaded IRQs minimizes interrupts-off critical > sections. >
I think in this case threaded IRQ would just add unnecessary overhead. There are no scanning delays, just a few register reads and writes. Input core will take some cycles propagating the events but it disables interrupts anyway. Setting up a separate thread and scheduling does not make much sense here. Also I am not sure if arches with large number of interrupts would want to move to all threaded interrupts model. -- Dmitry -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html