Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932669Ab3E2Pnn (ORCPT ); Wed, 29 May 2013 11:43:43 -0400 Received: from g4t0015.houston.hp.com ([15.201.24.18]:25958 "EHLO g4t0015.houston.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757797Ab3E2Pnh convert rfc822-to-8bit (ORCPT ); Wed, 29 May 2013 11:43:37 -0400 From: "Pearson, Greg" To: "Dall, Elizabeth J (MCLinux)" CC: "rjw@sisk.pl" , "bhelgaas@google.com" , "ying.huang@intel.com" , "linux-acpi@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-pci@vger.kernel.org" Subject: Re: [PATCH 3/3] PCI/AER: Provide reset_link for firmware first root port Thread-Topic: [PATCH 3/3] PCI/AER: Provide reset_link for firmware first root port Thread-Index: AQHOXIMfWPUbKGAb7UyF7S06eh+fzw== Date: Wed, 29 May 2013 15:42:27 +0000 Message-ID: <51A621E2.2050202@hp.com> References: <1369766929-4386-1-git-send-email-betty.dall@hp.com> <1369766929-4386-4-git-send-email-betty.dall@hp.com> In-Reply-To: <1369766929-4386-4-git-send-email-betty.dall@hp.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: user-agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130329 Thunderbird/17.0.5 x-originating-ip: [16.210.16.251] Content-Type: text/plain; charset=US-ASCII Content-ID: Content-Transfer-Encoding: 7BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3431 Lines: 88 On 05/28/2013 12:48 PM, Betty Dall wrote: > The firmware first path does not install the aerdrv root port > service driver, so the firmware first root port does not have > a reset_link callback. When a firmware first root port does not have > a reset_link callback, use a new default reset_link similar to what > we already do for the default_downstream_reset_link(). The firmware > first default reset_link brings the root port out of SBR if firmware > left it in SBR. > > Signed-off-by: Betty Dall > --- > > drivers/pci/pcie/aer/aerdrv_core.c | 37 ++++++++++++++++++++++++++++++++++++ > 1 files changed, 37 insertions(+), 0 deletions(-) > > > diff --git a/drivers/pci/pcie/aer/aerdrv_core.c b/drivers/pci/pcie/aer/aerdrv_core.c > index 8ec8b4f..6862fe3 100644 > --- a/drivers/pci/pcie/aer/aerdrv_core.c > +++ b/drivers/pci/pcie/aer/aerdrv_core.c > @@ -413,6 +413,40 @@ static pci_ers_result_t default_downstream_reset_link(struct pci_dev *dev) > return PCI_ERS_RESULT_RECOVERED; > } > > +/** > + * default_ff_root_port_reset_link - default reset function for firmware > + * first Root Port > + * @dev: pointer to root port's pci_dev data structure > + * > + * Invoked when performing link reset at Root Port w/ no aer driver. > + * This happens through the firmware first path. Firmware may leave > + * the Root Port in SBR and it is the OS responsiblity to bring it out > + * of SBR. > + */ > +static pci_ers_result_t default_ff_root_port_reset_link(struct pci_dev *dev) > +{ > + u16 p2p_ctrl; > + > + /* Read Secondary Bus Reset */ > + pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &p2p_ctrl); > + p2p_ctrl |= PCI_BRIDGE_CTL_BUS_RESET; Remove "p2p_ctrl |= PCI_BRIDGE_CTL_BUS_RESET;" otherwise the following conditional is always taken. -- Greg > + > + /* De-assert Secondary Bus Reset, if it is set */ > + if (p2p_ctrl & PCI_BRIDGE_CTL_BUS_RESET) { > + p2p_ctrl &= ~PCI_BRIDGE_CTL_BUS_RESET; > + pci_write_config_word(dev, PCI_BRIDGE_CONTROL, p2p_ctrl); > + > + /* > + * System software must wait for at least 100ms from the end > + * of a reset of one or more device before it is permitted > + * to issue Configuration Requests to those devices. > + */ > + msleep(200); > + dev_dbg(&dev->dev, "Root Port link has been reset\n"); > + } > + return PCI_ERS_RESULT_RECOVERED; > +} > + > static int find_aer_service_iter(struct device *device, void *data) > { > struct pcie_port_service_driver *service_driver, **drv; > @@ -460,6 +494,9 @@ static pci_ers_result_t reset_link(struct pci_dev *dev) > status = driver->reset_link(udev); > } else if (pci_pcie_type(udev) == PCI_EXP_TYPE_DOWNSTREAM) { > status = default_downstream_reset_link(udev); > + } else if (pci_pcie_type(udev) == PCI_EXP_TYPE_ROOT_PORT && > + pcie_aer_get_firmware_first(udev)) { > + status = default_ff_root_port_reset_link(udev); > } else { > dev_printk(KERN_DEBUG, &dev->dev, > "no link-reset support at upstream device %s\n", > -- > To unsubscribe from this list: send the line "unsubscribe linux-pci" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- 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/