Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757337Ab0LKARh (ORCPT ); Fri, 10 Dec 2010 19:17:37 -0500 Received: from mail-qy0-f174.google.com ([209.85.216.174]:34850 "EHLO mail-qy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756378Ab0LKARg (ORCPT ); Fri, 10 Dec 2010 19:17:36 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=sender:message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:content-type:content-transfer-encoding; b=UgVg63vYHiFHzJ38BVGlyB0KxIf4Zku/STsHnfODPFk39aehapEewRBU9D0tda9YHL Ej45wTFYGgv5qouLawIBxQy6UbUj28P2zRITOAPQt+OUImmQtsZJno33bOnTjZjIG/08 2et1sD0Q7kSKyQZ45Kj3k8S2NyV1jnVqLRnGg= Message-ID: <4D02C336.707@lwfinger.net> Date: Fri, 10 Dec 2010 18:17:58 -0600 From: Larry Finger User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.15) Gecko/20101026 SUSE/3.0.10 Thunderbird/3.0.10 MIME-Version: 1.0 To: Alan Stern CC: pali.rohar@gmail.com, Greg Kroah-Hartman , USB list , LKML Subject: Re: [RFC/RFT] OHCI: Fix for regression in 2.6.37-rc1 since commit 3df7169e7 References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2264 Lines: 57 Alan, The box with the problem has been repaired, and I am trying to debug it. What I have learned so far: The "unable to enumerate" message is triggered because PORT_OWNER is not set in the status register. So far, I have found that this bit is set in only 4 places: 1. set_owner() 2. store_companion() 3. ehci_hub_control() 4. ehci_relinquish_port() 5. check_reset_complete() Of these, only #5 is called before the first enumeration message is logged, but it is only called with arguments that never set the PORT_OWNED bit in the status. At this point I'm at a loss. Could you please give me ideas on where I might look. The logged data leading up to the first message are: [ 3.002762] hub 4-0:1.0: USB hub found [ 3.002780] hub 4-0:1.0: 5 ports detected [ 3.088286] ehci_hcd 0000:00:02.1: usb: Entered check_reset_complete with port_status 0x1005 [ 3.088433] ehci_hcd 0000:00:02.1: port 4 high speed [ 3.144061] usb 1-4: new high speed USB device using ehci_hcd and address 2 [ 3.200286] ehci_hcd 0000:00:02.1: usb: Entered check_reset_complete with port_status 0x1005 [ 3.200437] ehci_hcd 0000:00:02.1: port 4 high speed [ 3.352298] ehci_hcd 0000:00:02.1: usb: Entered check_reset_complete with port_status 0x1005 [ 3.352304] ehci_hcd 0000:00:02.1: port 5 high speed [ 3.408071] usb 1-5: new high speed USB device using ehci_hcd and address 3 [ 3.454449] PM: Starting manual resume from disk [ 3.464305] ehci_hcd 0000:00:02.1: usb: Entered check_reset_complete with port_status 0x1005 [ 3.464449] ehci_hcd 0000:00:02.1: port 5 high speed [ 3.600052] ehci_hcd 0000:00:04.1: usb: Entered check_reset_complete with port_status 0x1001 [ 3.600202] ehci_hcd 0000:00:04.1: port 5 full speed --> companion [ 3.600307] ehci_hcd 0000:00:04.1: Wrote 0x3001 to status reg [ 3.656089] hub 2-0:1.0: unable to enumerate USB device on port 5 [ 3.656203] ehci_hcd 0000:00:04.1: In ehci_relinquish_port [ 3.656295] ehci_hcd 0000:00:04.1: In set_owner Thanks, Larry -- 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/