diff options
| -rw-r--r-- | drivers/pci/pci.c | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index cc232c016ef9..e98c8104297b 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -38,6 +38,19 @@ EXPORT_SYMBOL(pci_pci_problems); unsigned int pci_pm_d3_delay; +static void pci_pme_list_scan(struct work_struct *work); + +static LIST_HEAD(pci_pme_list); +static DEFINE_MUTEX(pci_pme_list_mutex); +static DECLARE_DELAYED_WORK(pci_pme_work, pci_pme_list_scan); + +struct pci_pme_device { + struct list_head list; + struct pci_dev *dev; +}; + +#define PME_TIMEOUT 1000 /* How long between PME checks */ + static void pci_dev_d3_sleep(struct pci_dev *dev) { unsigned int delay = dev->d3_delay; @@ -1331,6 +1344,32 @@ bool pci_pme_capable(struct pci_dev *dev, pci_power_t state) return !!(dev->pme_support & (1 << state)); } +static void pci_pme_list_scan(struct work_struct *work) +{ + struct pci_pme_device *pme_dev; + + mutex_lock(&pci_pme_list_mutex); + if (!list_empty(&pci_pme_list)) { + list_for_each_entry(pme_dev, &pci_pme_list, list) + pci_pme_wakeup(pme_dev->dev, NULL); + schedule_delayed_work(&pci_pme_work, msecs_to_jiffies(PME_TIMEOUT)); + } + mutex_unlock(&pci_pme_list_mutex); +} + +/** + * pci_external_pme - is a device an external PCI PME source? + * @dev: PCI device to check + * + */ + +static bool pci_external_pme(struct pci_dev *dev) +{ + if (pci_is_pcie(dev) || dev->bus->number == 0) + return false; + return true; +} + /** * pci_pme_active - enable or disable PCI device's PME# function * @dev: PCI device to handle. @@ -1354,6 +1393,44 @@ void pci_pme_active(struct pci_dev *dev, bool enable) pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, pmcsr); + /* PCI (as opposed to PCIe) PME requires that the device have + its PME# line hooked up correctly. Not all hardware vendors + do this, so the PME never gets delivered and the device + remains asleep. The easiest way around this is to + periodically walk the list of suspended devices and check + whether any have their PME flag set. The assumption is that + we'll wake up often enough anyway that this won't be a huge + hit, and the power savings from the devices will still be a + win. */ + + if (pci_external_pme(dev)) { + struct pci_pme_device *pme_dev; + if (enable) { + pme_dev = kmalloc(sizeof(struct pci_pme_device), + GFP_KERNEL); + if (!pme_dev) + goto out; + pme_dev->dev = dev; + mutex_lock(&pci_pme_list_mutex); + list_add(&pme_dev->list, &pci_pme_list); + if (list_is_singular(&pci_pme_list)) + schedule_delayed_work(&pci_pme_work, + msecs_to_jiffies(PME_TIMEOUT)); + mutex_unlock(&pci_pme_list_mutex); + } else { + mutex_lock(&pci_pme_list_mutex); + list_for_each_entry(pme_dev, &pci_pme_list, list) { + if (pme_dev->dev == dev) { + list_del(&pme_dev->list); + kfree(pme_dev); + break; + } + } + mutex_unlock(&pci_pme_list_mutex); + } + } + +out: dev_printk(KERN_DEBUG, &dev->dev, "PME# %s\n", enable ? "enabled" : "disabled"); } |