Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751451Ab3E2QRO (ORCPT ); Wed, 29 May 2013 12:17:14 -0400 Received: from g5t0009.atlanta.hp.com ([15.192.0.46]:43951 "EHLO g5t0009.atlanta.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760187Ab3E2QQw (ORCPT ); Wed, 29 May 2013 12:16:52 -0400 Message-ID: <1369844192.12792.3.camel@ejdallLaptop> Subject: Re: [PATCH 3/3] PCI/AER: Provide reset_link for firmware first root port From: Betty Dall To: "Pearson, Greg" 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" Date: Wed, 29 May 2013 10:16:32 -0600 In-Reply-To: <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> <51A621E2.2050202@hp.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.2- 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: 3728 Lines: 95 On Wed, 2013-05-29 at 09:42 -0600, Pearson, Greg wrote: > 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 Agreed. That was a copy and paste mistake. I will fix and retest. -Betty > > + > > + /* 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/