From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932119AbWFFHnn (ORCPT ); Tue, 6 Jun 2006 03:43:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932122AbWFFHnn (ORCPT ); Tue, 6 Jun 2006 03:43:43 -0400 Received: from mail1.kontent.de ([81.88.34.36]:9097 "EHLO Mail1.KONTENT.De") by vger.kernel.org with ESMTP id S932119AbWFFHnm (ORCPT ); Tue, 6 Jun 2006 03:43:42 -0400 From: Oliver Neukum To: David Brownell Subject: Re: [linux-usb-devel] USB devices fail unnecessarily on unpowered hubs Date: Tue, 6 Jun 2006 09:43:58 +0200 User-Agent: KMail/1.8 Cc: linux-usb-devel@lists.sourceforge.net, Pavel Machek , David Liontooth , linux-kernel@vger.kernel.org References: <447EB0DC.4040203@cogweb.net> <200606031129.54580.oliver@neukum.org> <200606050732.53496.david-b@pacbell.net> In-Reply-To: <200606050732.53496.david-b@pacbell.net> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200606060943.59072.oliver@neukum.org> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Am Montag, 5. Juni 2006 16:32 schrieb David Brownell: > On Saturday 03 June 2006 2:29 am, Oliver Neukum wrote: > > If that does the job we need to somehow inherit the power supply maximum from > > PCI when we allocate the root hub's device structure. > > I don't think there is such a convention that's generic for PCI. There might > be ACPI-specific tables holding that value, but on embedded hardware the model > is often that the arch/.../board-ZZZ.c file just "knows" things like how much > power the regulator powering that port can provide, and arranges bus_mA to match. > Just like it knows all sorts of other details about how that board works. Yes, I am afraid it cannot be done on the fly. But we might use a symbolic define which a subarch can override instead of a literal "500". If it turns out that this problem is one of power and not some other deficiency of this system's root hub. Regards Oliver