From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262863AbVGHUEM (ORCPT ); Fri, 8 Jul 2005 16:04:12 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262860AbVGHUEB (ORCPT ); Fri, 8 Jul 2005 16:04:01 -0400 Received: from mx2.elte.hu ([157.181.151.9]:10407 "EHLO mx2.elte.hu") by vger.kernel.org with ESMTP id S262859AbVGHUDL (ORCPT ); Fri, 8 Jul 2005 16:03:11 -0400 Date: Fri, 8 Jul 2005 22:03:15 +0200 From: Ingo Molnar To: Doug Maxey Cc: "K.R. Foley" , linux-kernel Subject: Re: Real-Time Preemption -RT-V0.7.51-17 - Keyboard Problems Message-ID: <20050708200315.GA31100@elte.hu> References: <20050708191326.GA6503@elte.hu> <200507081935.j68JZSqr003200@falcon30.maxeymade.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200507081935.j68JZSqr003200@falcon30.maxeymade.com> User-Agent: Mutt/1.4.2.1i X-ELTE-SpamVersion: MailScanner 4.31.6-itk1 (ELTE 1.2) SpamAssassin 2.63 ClamAV 0.73 X-ELTE-VirusStatus: clean X-ELTE-SpamCheck: no X-ELTE-SpamCheck-Details: score=-4.9, required 5.9, autolearn=not spam, BAYES_00 -4.90 X-ELTE-SpamLevel: X-ELTE-SpamScore: -4 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org * Doug Maxey wrote: > FWIW, I have seen this issue under USB, off and on since about 2.6.9. > Never have dug into it, was always simpler to just unplug and re-plug > the keyboard. Of course, this predates RT. hm, doesnt this coincide with the pushing of some keyboard functionality (such as LED handling, etc.) into keventd? Keyboard stuff used to be done from a tasklet, but that had its own problems. Now that we use keventd (which is a SCHED_OTHER task) the delays seen by the keyboard handling path might be larger. This could both affect the hardware (keyboards are quite fragile), or it could also trigger some races that were not triggered that often with tasklets? Ingo