From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Brownell Subject: Re: status of USB on omap35xx ? Date: Thu, 11 Dec 2008 18:16:17 -0800 Message-ID: <200812111816.17860.david-b@pacbell.net> References: <1228870250.32014.148.camel@localhost.localdomain> <6ed0b2680812111452t75b175bdr304e9b1d22ea93de@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from smtp123.sbc.mail.sp1.yahoo.com ([69.147.64.96]:41040 "HELO smtp123.sbc.mail.sp1.yahoo.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1756429AbYLLCQU (ORCPT ); Thu, 11 Dec 2008 21:16:20 -0500 In-Reply-To: <6ed0b2680812111452t75b175bdr304e9b1d22ea93de@mail.gmail.com> Content-Disposition: inline Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Grazvydas Ignotas Cc: Paul Walmsley , Steve Sakoman , Tony Lindgren , me@felipebalbi.com, Jeff Steele , linux-omap On Thursday 11 December 2008, Grazvydas Ignotas wrote: > Curiously at this point I can plug/unplug to my ext hub any additional > devices as much as I want, as long as I keep the first device plugged. > If I unplug all devices from ext hub, I get suspend and kernel no > longer reacts to any replugs. Sounds like one issue might be that EHCI isn't waking up the way it should, when it gets "remote wakeup" signaling from USB. The USB host drivers go to some effort to put themselves in as low a runtime power state as practical, and rely on the hardware to wake up given events like insertion/removal of an external device, or the downstream device issuing wakeup signaling (e.g. press a key on a keyboard that went to sleep). OMAP has been known to need special attention to kick in such wakeup mechanisms. Maybe this is another such case. - Dave