Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758562AbXJLUX2 (ORCPT ); Fri, 12 Oct 2007 16:23:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755443AbXJLUXS (ORCPT ); Fri, 12 Oct 2007 16:23:18 -0400 Received: from nf-out-0910.google.com ([64.233.182.186]:35781 "EHLO nf-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755032AbXJLUXR (ORCPT ); Fri, 12 Oct 2007 16:23:17 -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=RrMB9L52IYf+fQItYIbDRrn83OmqT7ZZkEHO79QC3dG/2t7dLwKQxeKzs3l76US4toQ96y6+ri2xnYTKD8JPiKGWSZ+2Tp9IdNUxUMxQCdM0r4ZvB0G5cQxWVgo9dXbaNSRQ6j6I1h8e+9QkIbKP1FQUnJqPPGog+4zJ2Xp9Z8E= Message-ID: Date: Fri, 12 Oct 2007 16:23:15 -0400 From: "Dmitry Torokhov" To: "Ahmed S. Darwish" Subject: Re: [PATCH try #2] Input/Joystick Driver: add support AD7142 joystick driver Cc: "Bryan Wu" , 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: <20071012192111.GB12559@Ahmed> 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> <20071012164131.GA12559@Ahmed> <20071012192111.GB12559@Ahmed> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1502 Lines: 37 On 10/12/07, Ahmed S. Darwish wrote: > On Fri, Oct 12, 2007 at 01:29:31PM -0400, Dmitry Torokhov wrote: > > > > > Isn't disabling device interrupts from the begining of the ISR "ad7142_interrupt" > > > till the kthread "ad7142_thread" got waked-up and scheduled a long time, > > > espicially if there's a high load on the userspace side ? > > > > > > > It is OK - you disable a specific interrupt line preventing it from > > raising any more IRQs until current one is serviced. > > Won't this affect system responsiveness if the IRQ line was shared ? You are right, this would not work in case of shared IRQs. Hovewer this driver is for an embedded arch and the line is not shared. > > > > > This is different from disabling interrupts on CPU. > > > > mm, Why disabling interrupts in general. Doesn't IRQ hanlers of the same kind got > executed in a serialized fashion even on SMPs ?. If so, why not just wakeup our > custom-thread or use workqueues and let them do their business ? Because you don't want CPU to be continually interrupted while untill right thread gets scheduled. I think using work[queue] is the best solution for this driver, but you still want to mask that particular IRQ off until you do the read. -- 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/