Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932825AbXJLQev (ORCPT ); Fri, 12 Oct 2007 12:34:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1761386AbXJLQOd (ORCPT ); Fri, 12 Oct 2007 12:14:33 -0400 Received: from ug-out-1314.google.com ([66.249.92.171]:45900 "EHLO ug-out-1314.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761379AbXJLQOb (ORCPT ); Fri, 12 Oct 2007 12:14:31 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=A1XtBlp06W5ztqC2lF7pM8M+i5J02Rdh/loMvnw6nBi/pLcT1Iz+rufb7ZwyI/vanm7OVw03QkTmF4y4CSpze1EASJXjShLaih5qRGcp4KsdvrzlbWvtAUrFCvu+CaVB4OY42ECCy/HEm/IvVRMU9Qx/tOkf4Xk0MLgdW7Isqz0= Message-ID: Date: Fri, 12 Oct 2007 12:14:28 -0400 From: "Dmitry Torokhov" To: bryan.wu@analog.com Subject: Re: [PATCH try #2] Input/Joystick Driver: add support AD7142 joystick driver Cc: linux-input@atrey.karlin.mff.cuni.cz, linux-joystick@atrey.karlin.mff.cuni.cz, linux-kernel@vger.kernel.org, akpm@linux-foundation.org In-Reply-To: <1192204757.7089.9.camel@roc-laptop> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <1192174727.6247.20.camel@roc-laptop> <1192203593.7089.4.camel@roc-laptop> <1192204757.7089.9.camel@roc-laptop> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2058 Lines: 55 On 10/12/07, Bryan Wu wrote: > On Fri, 2007-10-12 at 11:50 -0400, Dmitry Torokhov wrote: > > On 10/12/07, Bryan Wu wrote: > > > On Fri, 2007-10-12 at 10:49 -0400, Dmitry Torokhov wrote: > > > > Hi Bryan, > > > > > > > > On 10/12/07, Bryan Wu wrote: > > > > > + > > > [snip] > > > > > + > > > > > +static void ad7142_close(struct input_dev *dev) > > > > > +{ > > > > > + free_irq(CONFIG_BFIN_JOYSTICK_IRQ_PFX, ad7142_interrupt); > > > > > + kthread_stop(ad7142_task); > > > > > > > > Don't you need to write something over i2c to shut the devoce off? > > > > What stops it from continuing to generate interrupts? > > > > > > > Actually, I am going to use "completion" to replace the whole > > > wait_interrupt_xxx and intr_flag things which original from Aubrey. How > > > do you think of that? > > > > > > > I don't think it is a very good idea - for me completion is one-time > > deal. You use it and then you are done. How about firing a work from > > interrupt and either rely on the default workqueue (keventd) or create > > your own to execute it? > > > > completion is a wrapper of workqueue and simpler to use. > my method: > 1. In kthread: > do { > |_______|_______wait_for_completion(&ad7142_completion); > |_______|_______ad7142_decode(); > |_______|_______enable_irq(CONFIG_BFIN_JOYSTICK_IRQ_PFX); > |_______} while (!kthread_should_stop()); > > 2. In irq handler will fire "complete(&ad7142_completion);" > > This is simpler and understand easier > You also need to re-initialize completion every time you done processing in kthread otherwise you will be constantly doing ad7142_decode(). Plus, how are you going to stop kthread (completion may not be signalled for a long time if nobody touches the joystick). -- Dmitry - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/