Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754137Ab3HBPmx (ORCPT ); Fri, 2 Aug 2013 11:42:53 -0400 Received: from hqemgate14.nvidia.com ([216.228.121.143]:8373 "EHLO hqemgate14.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754046Ab3HBPmv convert rfc822-to-8bit (ORCPT ); Fri, 2 Aug 2013 11:42:51 -0400 X-PGP-Universal: processed; by hqnvupgp08.nvidia.com on Fri, 02 Aug 2013 08:41:20 -0700 Message-ID: <51FBD377.8060705@nvidia.com> Date: Fri, 2 Aug 2013 18:42:47 +0300 From: Tuomas Tynkkynen User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130330 Thunderbird/17.0.5 MIME-Version: 1.0 To: Matthieu CASTET CC: "balbi@ti.com" , "linux-tegra@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-usb@vger.kernel.org" , "swarren@wwwdotorg.org" , "gregkh@linuxfoundation.org" , "stern@rowland.harvard.edu" , Alexander Shishkin Subject: Re: [PATCH 1/6] usb: host: add has_tdi_phy_lpm capability bit References: <1375292522-7855-1-git-send-email-ttynkkynen@nvidia.com> <1375292522-7855-2-git-send-email-ttynkkynen@nvidia.com> <20130801100544.76233b42@parrot.com> In-Reply-To: <20130801100544.76233b42@parrot.com> Content-Type: text/plain; charset="ISO-8859-15" Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2176 Lines: 53 On 08/01/2013 11:05 AM, Matthieu CASTET wrote: > Hi, > > Le Wed, 31 Jul 2013 18:41:57 +0100, > Tuomas Tynkkynen a ?crit : > >> The has_hostpc capability bit indicates that the host controller has >> the HOSTPC register extensions, but at the same time enables clock >> disabling power saving features with the PHY Low Power Clock Disable >> (PHCD) bit. >> >> However, some host controllers have the HOSTPC extensions but don't >> support the low-power feature, so the PHCD bit must not be set on >> those controllers. Add a separate capability bit for the low-power >> feature instead, and change all existing users of has_hostpc to use >> this new capability bit. >> >> The idea for this commit is taken from an old 2012 commit that never >> got merged ("disociate chipidea PHY low power suspend control from >> hostpc") > Note that because of the different register layout (see "add phy low > power suspend for older chipidea core" commit in the same series), we > should not set has_tdi_phy_lpm if has_hostpc == 0 with the current code. > > May be you should have change the ehci->has_hostpc to (ehci->has_hostpc > && ehci->has_tdi_phy_lpm). Hmm, I see. Do you think there could be a case where that could get accidentally get triggered via autodetection? That patch series seems to set either both or neither. And I figure no one will be explicitly setting that flag (if has_hostpc == 0) without implementing the non-has_hostpc case first. > > BTW Alan make some comment on the commit : > http://marc.info/?l=linux-usb&m=133701342028213&w=2 > > They may apply to your commit. > >> >> Inspired-by: Matthieu CASTET >> Signed-off-by: Tuomas Tynkkynen >> --- >> drivers/usb/chipidea/host.c | 1 + >> drivers/usb/host/ehci-hub.c | 14 +++++++------- >> drivers/usb/host/ehci.h | 1 + >> 3 files changed, 9 insertions(+), 7 deletions(-) >> -- 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/