From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760691AbZCYAyH (ORCPT ); Tue, 24 Mar 2009 20:54:07 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758773AbZCYAmb (ORCPT ); Tue, 24 Mar 2009 20:42:31 -0400 Received: from ogre.sisk.pl ([217.79.144.158]:40042 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758913AbZCYAm2 (ORCPT ); Tue, 24 Mar 2009 20:42:28 -0400 From: "Rafael J. Wysocki" To: Jesse Barnes Subject: [RFC][PATCH 1/2] PCI PM: Introduce __pci_[start|complete]_power_transition() Date: Wed, 25 Mar 2009 01:41:07 +0100 User-Agent: KMail/1.11.1 (Linux/2.6.29-rc8-tst; KDE/4.2.1; x86_64; ; ) Cc: Benjamin Herrenschmidt , Linux PCI , pm list , LKML , Andrew Morton References: <200903250138.53234.linux-pci-owner@vger.kernel.org> In-Reply-To: <200903250138.53234.linux-pci-owner@vger.kernel.org> MIME-Version: 1.0 Content-Disposition: inline Message-Id: <200903250141.08478.rjw@sisk.pl> 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 From: Rafael J. Wysocki The radeonfb driver needs to program the device's PMCSR directly due to some quirky hardware it has to handle (see http://bugzilla.kernel.org/show_bug.cgi?id=12846 for details) and after doing that it needs to call the platform (usually ACPI) to finish the power transition of the device. Currently it uses pci_set_power_state() for this purpose, however making a specific assumption about the internal behavior of this function, which has changed recently so that this assumption is no longer satisfied. For this reason, introduce __pci_complete_power_transition() that may be called by the radeonfb driver to complete the power transition of the device. For symmetry, introduce __pci_start_power_transition(). Signed-off-by: Rafael J. Wysocki --- drivers/pci/pci.c | 66 +++++++++++++++++++++++++++++++++++++--------------- include/linux/pci.h | 1 2 files changed, 49 insertions(+), 18 deletions(-) Index: linux-2.6/drivers/pci/pci.c =================================================================== --- linux-2.6.orig/drivers/pci/pci.c +++ linux-2.6/drivers/pci/pci.c @@ -540,6 +540,50 @@ void pci_update_current_state(struct pci } /** + * pci_platform_power_transition - Use platform to change device power state + * @dev: PCI device to handle. + * @state: State to put the device into. + */ +static int pci_platform_power_transition( + struct pci_dev *dev, pci_power_t state) +{ + int error = 0; + + if (platform_pci_power_manageable(dev)) + error = platform_pci_set_power_state(dev, state); + + if (!error) + pci_update_current_state(dev, state); + + return error; +} + +/** + * __pci_start_power_transition - Start power transition of a PCI device + * @dev: PCI device to handle. + * @state: State to put the device into. + */ +static void __pci_start_power_transition(struct pci_dev *dev, pci_power_t state) +{ + if (state == PCI_D0) + pci_platform_power_transition(dev, PCI_D0); +} + +/** + * __pci_complete_power_transition - Complete power transition of a PCI device + * @dev: PCI device to handle. + * @state: State to put the device into. + * + * This function should not be called directly by device drivers. + */ +int __pci_complete_power_transition(struct pci_dev *dev, pci_power_t state) +{ + return state > PCI_D0 ? + pci_platform_power_transition(dev, state) : -ENODEV; +} +EXPORT_SYMBOL_GPL(__pci_complete_power_transition); + +/** * pci_set_power_state - Set the power state of a PCI device * @dev: PCI device to handle. * @state: PCI power state (D0, D1, D2, D3hot) to put the device into. @@ -575,16 +619,8 @@ int pci_set_power_state(struct pci_dev * if (dev->current_state == state) return 0; - if (state == PCI_D0) { - /* - * Allow the platform to change the state, for example via ACPI - * _PR0, _PS0 and some such, but do not trust it. - */ - int ret = platform_pci_power_manageable(dev) ? - platform_pci_set_power_state(dev, PCI_D0) : 0; - if (!ret) - pci_update_current_state(dev, PCI_D0); - } + __pci_start_power_transition(dev, state); + /* This device is quirked not to be put into D3, so don't put it in D3 */ if (state == PCI_D3hot && (dev->dev_flags & PCI_DEV_FLAGS_NO_D3)) @@ -592,14 +628,8 @@ int pci_set_power_state(struct pci_dev * error = pci_raw_set_power_state(dev, state); - if (state > PCI_D0 && platform_pci_power_manageable(dev)) { - /* Allow the platform to finalize the transition */ - int ret = platform_pci_set_power_state(dev, state); - if (!ret) { - pci_update_current_state(dev, state); - error = 0; - } - } + if (!__pci_complete_power_transition(dev, state)) + error = 0; return error; } Index: linux-2.6/include/linux/pci.h =================================================================== --- linux-2.6.orig/include/linux/pci.h +++ linux-2.6/include/linux/pci.h @@ -689,6 +689,7 @@ size_t pci_get_rom_size(struct pci_dev * /* Power management related routines */ int pci_save_state(struct pci_dev *dev); int pci_restore_state(struct pci_dev *dev); +int __pci_complete_power_transition(struct pci_dev *dev, pci_power_t state); int pci_set_power_state(struct pci_dev *dev, pci_power_t state); pci_power_t pci_choose_state(struct pci_dev *dev, pm_message_t state); bool pci_pme_capable(struct pci_dev *dev, pci_power_t state);