| Message ID | 1250666656.23178.118.camel@sli10-desk.sh.intel.com (mailing list archive) |
|---|---|
| State | RFC, archived |
| Headers | show |
On Wednesday 19 August 2009, Shaohua Li wrote: > Add an implementation how to detect wakeup event for PCI bus level. PCI device > can invoke PME and platform or PCIe native approach can collect the PME and > reports to OS. OS should identify exactly which device invokes PME as several > devices can share interrupts. > > In platform approach (ACPI in this case), some BIOS give exact device which > invokes PME but others doesn't. > In PCIe native approach, if PME source device is a pcie endpoint, the device > is the exact PME source. If the device is root port or pcie-to-pci bridge, > we need scan the hierarchy under the device. > > To identify PME source, the patch does: > 1. if the source is a pci device, the device is the only source for PME > 2. if the source is a bridge, scan the hierarchy under the bridge. Several > devices under the bridge could be the source. > > > --- > drivers/pci/pci-driver.c | 90 +++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 90 insertions(+) > > Index: linux/drivers/pci/pci-driver.c > =================================================================== > --- linux.orig/drivers/pci/pci-driver.c 2009-08-19 13:43:18.000000000 +0800 > +++ linux/drivers/pci/pci-driver.c 2009-08-19 13:50:29.000000000 +0800 > @@ -570,6 +570,95 @@ static void pci_pm_complete(struct devic > drv->pm->complete(dev); > } > > +/* > + * Called when dev is suspected to invoke a wakeup event > + * */ > +static bool pci_handle_one_wakeup_event(struct pci_dev *pdev) > +{ > + int pme_pos = pdev->pm_cap; > + struct pci_driver *drv = pdev->driver; > + u16 pmcsr; > + bool spurious = false; > + > + if (pme_pos == 0) { > + /* > + * Some USB devices haven't PME, but have specific registers to > + * control wakeup > + */ > + goto out; > + } > + > + /* clear PME status and disable PME to avoid interrupt flood */ > + pci_read_config_word(pdev, pme_pos + PCI_PM_CTRL, &pmcsr); > + if (!(pmcsr & PCI_PM_CTRL_PME_STATUS)) > + return false; > + /* I see spurious PME here, just ignore it for now */ > + if (!(pmcsr & PCI_PM_CTRL_PME_ENABLE)) > + spurious = true; > + else > + pmcsr &= ~PCI_PM_CTRL_PME_ENABLE; > + pmcsr |= PCI_PM_CTRL_PME_STATUS; > + pci_write_config_word(pdev, pme_pos + PCI_PM_CTRL, pmcsr); > + > + if (spurious) > + return false; > + return true; > +out: > + if (drv && drv->driver.pm && drv->driver.pm->wakeup_event) > + return drv->driver.pm->wakeup_event(&pdev->dev); > + return false; > +} > + > +static bool pci_pm_wakeup_event(struct device *dev) > +{ > + bool ret; > + struct pci_dev *tmp = NULL, *target = to_pci_dev(dev); > + int domain_nr, bus_start, bus_end; > + > + /* > + * @target could be a bridge or a device. > + * PCIe native PME case: > + * @target is device - @target must be the exact device invoking PME > + * @target is a root port or pcie-pci bridge - should scan legacy pci > + * devices under the bridge > + * ACPI GPE case: > + * @target is device - AML code could clear PME status before this > + * routine is called, so we can't detect if @target invokes PME. > + * Let's trust AML code > + * @target is bridge - scan devices under the bridge > + * So: if target is device, trust the device invokes PME. If target is > + * bridge, scan devices under the bridge and only trust device invokes > + * PME which we can detect > + **/ > + ret = pci_handle_one_wakeup_event(target); > + if (!target->subordinate || (target->is_pcie && > + target->pcie_type != PCI_EXP_TYPE_ROOT_PORT && > + target->pcie_type != PCI_EXP_TYPE_PCI_BRIDGE)) { > + /* always trust the device invokes PME even we can't detect */ > + device_receive_wakeup_event(&target->dev); How's that thing defined? We want to call pm_request_resume() at this point. > + return true; > + } > + > + if (ret) > + device_receive_wakeup_event(&target->dev); > + > + /* scan devices under the bridge */ > + domain_nr = pci_domain_nr(target->bus); > + bus_start = target->subordinate->secondary; > + bus_end = target->subordinate->subordinate; > + while ((tmp = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, tmp)) != NULL) { > + if (pci_domain_nr(tmp->bus) == domain_nr && > + tmp->bus->number >= bus_start && > + tmp->bus->number <= bus_end) { > + if (pci_handle_one_wakeup_event(tmp)) { > + ret = true; > + device_receive_wakeup_event(&tmp->dev); And here. > + } > + } > + } > + return ret; > +} > + > #ifdef CONFIG_SUSPEND > > static int pci_pm_suspend(struct device *dev) > @@ -925,6 +1014,7 @@ struct dev_pm_ops pci_dev_pm_ops = { > .thaw_noirq = pci_pm_thaw_noirq, > .poweroff_noirq = pci_pm_poweroff_noirq, > .restore_noirq = pci_pm_restore_noirq, > + .wakeup_event = pci_pm_wakeup_event, Please don't do that. > }; > > #define PCI_PM_OPS_PTR (&pci_dev_pm_ops) Best, Rafael -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Index: linux/drivers/pci/pci-driver.c =================================================================== --- linux.orig/drivers/pci/pci-driver.c 2009-08-19 13:43:18.000000000 +0800 +++ linux/drivers/pci/pci-driver.c 2009-08-19 13:50:29.000000000 +0800 @@ -570,6 +570,95 @@ static void pci_pm_complete(struct devic drv->pm->complete(dev); } +/* + * Called when dev is suspected to invoke a wakeup event + * */ +static bool pci_handle_one_wakeup_event(struct pci_dev *pdev) +{ + int pme_pos = pdev->pm_cap; + struct pci_driver *drv = pdev->driver; + u16 pmcsr; + bool spurious = false; + + if (pme_pos == 0) { + /* + * Some USB devices haven't PME, but have specific registers to + * control wakeup + */ + goto out; + } + + /* clear PME status and disable PME to avoid interrupt flood */ + pci_read_config_word(pdev, pme_pos + PCI_PM_CTRL, &pmcsr); + if (!(pmcsr & PCI_PM_CTRL_PME_STATUS)) + return false; + /* I see spurious PME here, just ignore it for now */ + if (!(pmcsr & PCI_PM_CTRL_PME_ENABLE)) + spurious = true; + else + pmcsr &= ~PCI_PM_CTRL_PME_ENABLE; + pmcsr |= PCI_PM_CTRL_PME_STATUS; + pci_write_config_word(pdev, pme_pos + PCI_PM_CTRL, pmcsr); + + if (spurious) + return false; + return true; +out: + if (drv && drv->driver.pm && drv->driver.pm->wakeup_event) + return drv->driver.pm->wakeup_event(&pdev->dev); + return false; +} + +static bool pci_pm_wakeup_event(struct device *dev) +{ + bool ret; + struct pci_dev *tmp = NULL, *target = to_pci_dev(dev); + int domain_nr, bus_start, bus_end; + + /* + * @target could be a bridge or a device. + * PCIe native PME case: + * @target is device - @target must be the exact device invoking PME + * @target is a root port or pcie-pci bridge - should scan legacy pci + * devices under the bridge + * ACPI GPE case: + * @target is device - AML code could clear PME status before this + * routine is called, so we can't detect if @target invokes PME. + * Let's trust AML code + * @target is bridge - scan devices under the bridge + * So: if target is device, trust the device invokes PME. If target is + * bridge, scan devices under the bridge and only trust device invokes + * PME which we can detect + **/ + ret = pci_handle_one_wakeup_event(target); + if (!target->subordinate || (target->is_pcie && + target->pcie_type != PCI_EXP_TYPE_ROOT_PORT && + target->pcie_type != PCI_EXP_TYPE_PCI_BRIDGE)) { + /* always trust the device invokes PME even we can't detect */ + device_receive_wakeup_event(&target->dev); + return true; + } + + if (ret) + device_receive_wakeup_event(&target->dev); + + /* scan devices under the bridge */ + domain_nr = pci_domain_nr(target->bus); + bus_start = target->subordinate->secondary; + bus_end = target->subordinate->subordinate; + while ((tmp = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, tmp)) != NULL) { + if (pci_domain_nr(tmp->bus) == domain_nr && + tmp->bus->number >= bus_start && + tmp->bus->number <= bus_end) { + if (pci_handle_one_wakeup_event(tmp)) { + ret = true; + device_receive_wakeup_event(&tmp->dev); + } + } + } + return ret; +} + #ifdef CONFIG_SUSPEND static int pci_pm_suspend(struct device *dev) @@ -925,6 +1014,7 @@ struct dev_pm_ops pci_dev_pm_ops = { .thaw_noirq = pci_pm_thaw_noirq, .poweroff_noirq = pci_pm_poweroff_noirq, .restore_noirq = pci_pm_restore_noirq, + .wakeup_event = pci_pm_wakeup_event, }; #define PCI_PM_OPS_PTR (&pci_dev_pm_ops)