Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754016AbaGBOCf (ORCPT ); Wed, 2 Jul 2014 10:02:35 -0400 Received: from iolanthe.rowland.org ([192.131.102.54]:49309 "HELO iolanthe.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751708AbaGBOCd (ORCPT ); Wed, 2 Jul 2014 10:02:33 -0400 Date: Wed, 2 Jul 2014 10:02:32 -0400 (EDT) From: Alan Stern X-X-Sender: stern@iolanthe.rowland.org To: Tuomas Tynkkynen cc: Greg Kroah-Hartman , Stephen Warren , Felipe Balbi , Philipp Zabel , , , , Subject: Re: [PATCH 0/3] Tegra USB probe order issue fix In-Reply-To: <1404248923-21086-1-git-send-email-ttynkkynen@nvidia.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2 Jul 2014, Tuomas Tynkkynen wrote: > Hi all, > > This series fixes a probe order issue with the Tegra EHCI driver. > Basically, the register area of the 1st USB controller contains some > registers that are global to all of the controllers, but that are also > cleared when reset is asserted to the 1st controller. So if (say) the > 3rd controller would be the first one to finish probing successfully, > then the reset that happens during the 1st controller's probe would > result in broken USB. So the before doing anything with the USB HW, > we should reset the 1st controller once, and then never ever reset > it again. This sounds very much like the sort of thing that ought to be described in DT. It is a hardware dependence, and DT exists for the purpose of describing the hardware. Alan Stern -- 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/