On Mon, Oct 15, 2007 at 11:48:17AM -0400, Dmitry Torokhov wrote: > Hi Bryan, > > On 10/15/07, Bryan Wu <[EMAIL PROTECTED]> wrote: > > + > > +static int ad7142_thread(void *nothing) > > +{ > > + do { > > + wait_for_completion(&ad7142_completion); > > + ad7142_decode(); > > + enable_irq(CONFIG_BFIN_JOYSTICK_IRQ_PFX); > > + } while (!kthread_should_stop()); > > + > > No, this is not going to work well: > - you at least need to reinitialize the completion before enabling > IRQ, otherwise you will spin in a very tight loop > - if noone would touch the joystick ad7142_clsoe would() block > infinitely because noone would signal the completion and > ad7142_thread() would never stop. > > Completion is just not a good abstraction here... Please use work > abstraction and possibly a separate workqueue. >
Bryan, I'm very interested in the technical advantage of using a completion here. In my _not-experienced_ opinion, I remember completions was created mainly for "create_task, wait till task got finished, go on" case. Why using it in a different context while workqueues was created for a similar situation to ad7142 one (non-irq context bottom-half) ? Regards, -- Ahmed S. Darwish HomePage: http://darwish.07.googlepages.com Blog: http://darwish-07.blogspot.com