Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756393AbXJIUl0 (ORCPT ); Tue, 9 Oct 2007 16:41:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754126AbXJIUlR (ORCPT ); Tue, 9 Oct 2007 16:41:17 -0400 Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:41026 "EHLO sunset.davemloft.net" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1753865AbXJIUlQ (ORCPT ); Tue, 9 Oct 2007 16:41:16 -0400 Date: Tue, 09 Oct 2007 13:41:16 -0700 (PDT) Message-Id: <20071009.134116.63997473.davem@davemloft.net> To: david-b@pacbell.net Cc: linux-usb-users@lists.sourceforge.net, linux-kernel@vger.kernel.org, greg@kroah.com Subject: Re: OHCI root_port_reset() deadly loop... From: David Miller In-Reply-To: <20071009163827.E7DB310B535@adsl-69-226-248-13.dsl.pltn13.pacbell.net> References: <20071009043643.773CC23715F@adsl-69-226-248-13.dsl.pltn13.pacbell.net> <20071008.214408.98397070.davem@davemloft.net> <20071009163827.E7DB310B535@adsl-69-226-248-13.dsl.pltn13.pacbell.net> X-Mailer: Mew version 5.1.52 on Emacs 21.4 / Mule 5.0 (SAKAKI) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1413 Lines: 36 From: David Brownell Date: Tue, 09 Oct 2007 09:38:27 -0700 > > > What values do you see for "portstat"? > > > > 0x111 > > That's unfortunately useless ... PPS, PRS, CCS (meaning powered, > resetting, connected). In short, there is *no* indication from > the OHCI hardware that a disconnect happened. But it's an excellent example of why my patch is mandatory. When the device gets into a stuck state, this code does the wrong thing. Instead of trying to deal with bad situations, it hangs the system instead. That sucks for anyone trying to debug something like this. This has caused weeks of debugging and grief for people, and it could have all been eliminated if this looping code were more robust to hardware failures. If you can't see why this is bad programming practice in a hardware driver, I will try to get my patch to someone who does. Even though I'm severly overloaded, you asked me for a patch, I gave you one. And now you want to push it back at me because it isn't clear to you yet that the code there right now is a huge problem. And all of this is independant of making sure EHCI loads first, we need to fix that too. - 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/