From 4f9c1397e2e80e52b17ec4e39760caa807bd15c7 Mon Sep 17 00:00:00 2001 From: Huang Ying Date: Wed, 8 Aug 2012 09:07:38 +0800 Subject: PCI/PM: Enable D3/D3cold by default for most devices This patch fixes the following bug: http://marc.info/?l=linux-usb&m=134318961120825&w=2 Originally, device lower power states include D1, D2, D3. After that, D3 is further divided into D3hot and D3cold. To support both scenario safely, original D3 is mapped to D3cold. When adding D3cold support, because worry about some device may have broken D3cold support, D3cold is disabled by default. This disable D3 on original platform too. But some original platform may only have working D3, but no working D1, D2. The root cause of the above bug is it too. To deal with this, this patch enables D3/D3cold by default for most devices. This restores the original behavior. For some devices that suspected to have broken D3cold support, such as PCIe port, D3cold is disabled by default. Reported-by: Bjorn Mork Signed-off-by: Huang Ying Signed-off-by: Bjorn Helgaas Reviewed-by: Rafael J. Wysocki --- drivers/pci/pcie/portdrv_pci.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'drivers/pci/pcie') diff --git a/drivers/pci/pcie/portdrv_pci.c b/drivers/pci/pcie/portdrv_pci.c index 3a7eefcb270..62f5a76c8f8 100644 --- a/drivers/pci/pcie/portdrv_pci.c +++ b/drivers/pci/pcie/portdrv_pci.c @@ -200,6 +200,11 @@ static int __devinit pcie_portdrv_probe(struct pci_dev *dev, return status; pci_save_state(dev); + /* + * D3cold may not work properly on some PCIe port, so disable + * it by default. + */ + dev->d3cold_allowed = false; if (!pci_match_id(port_runtime_pm_black_list, dev)) pm_runtime_put_noidle(&dev->dev); -- cgit v1.2.3-70-g09d2 From 3d8387efe1ad9eb5bfe8a2e58cdbd1b88b247eef Mon Sep 17 00:00:00 2001 From: Huang Ying Date: Wed, 15 Aug 2012 09:43:03 +0800 Subject: PCI/PM: Fix config reg access for D3cold and bridge suspending This patch fixes the following bug: http://marc.info/?l=linux-pci&m=134338059022620&w=2 Where lspci does not work properly if a device and the corresponding parent bridge (such as PCIe port) is suspended. This is because the device configuration space registers will be not accessible if the corresponding parent bridge is suspended or the device is put into D3cold state. To solve the issue, the bridge/PCIe port connected to the device is put into active state before read/write configuration space registers. If the device is in D3cold state, it will be put into active state too. To avoid resume/suspend PCIe port for each configuration register read/write, a small delay is added before the PCIe port to go suspended. Reported-by: Bjorn Mork Signed-off-by: Huang Ying Signed-off-by: Bjorn Helgaas Reviewed-by: Rafael J. Wysocki --- drivers/pci/pci-sysfs.c | 42 ++++++++++++++++++++++++++++++++++++++++++ drivers/pci/pcie/portdrv_pci.c | 9 +++++++++ 2 files changed, 51 insertions(+) (limited to 'drivers/pci/pcie') diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index 6869009c739..02d107b1528 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -458,6 +458,40 @@ boot_vga_show(struct device *dev, struct device_attribute *attr, char *buf) } struct device_attribute vga_attr = __ATTR_RO(boot_vga); +static void +pci_config_pm_runtime_get(struct pci_dev *pdev) +{ + struct device *dev = &pdev->dev; + struct device *parent = dev->parent; + + if (parent) + pm_runtime_get_sync(parent); + pm_runtime_get_noresume(dev); + /* + * pdev->current_state is set to PCI_D3cold during suspending, + * so wait until suspending completes + */ + pm_runtime_barrier(dev); + /* + * Only need to resume devices in D3cold, because config + * registers are still accessible for devices suspended but + * not in D3cold. + */ + if (pdev->current_state == PCI_D3cold) + pm_runtime_resume(dev); +} + +static void +pci_config_pm_runtime_put(struct pci_dev *pdev) +{ + struct device *dev = &pdev->dev; + struct device *parent = dev->parent; + + pm_runtime_put(dev); + if (parent) + pm_runtime_put_sync(parent); +} + static ssize_t pci_read_config(struct file *filp, struct kobject *kobj, struct bin_attribute *bin_attr, @@ -484,6 +518,8 @@ pci_read_config(struct file *filp, struct kobject *kobj, size = count; } + pci_config_pm_runtime_get(dev); + if ((off & 1) && size) { u8 val; pci_user_read_config_byte(dev, off, &val); @@ -529,6 +565,8 @@ pci_read_config(struct file *filp, struct kobject *kobj, --size; } + pci_config_pm_runtime_put(dev); + return count; } @@ -549,6 +587,8 @@ pci_write_config(struct file* filp, struct kobject *kobj, count = size; } + pci_config_pm_runtime_get(dev); + if ((off & 1) && size) { pci_user_write_config_byte(dev, off, data[off - init_off]); off++; @@ -587,6 +627,8 @@ pci_write_config(struct file* filp, struct kobject *kobj, --size; } + pci_config_pm_runtime_put(dev); + return count; } diff --git a/drivers/pci/pcie/portdrv_pci.c b/drivers/pci/pcie/portdrv_pci.c index 62f5a76c8f8..e76b44777db 100644 --- a/drivers/pci/pcie/portdrv_pci.c +++ b/drivers/pci/pcie/portdrv_pci.c @@ -140,9 +140,17 @@ static int pcie_port_runtime_resume(struct device *dev) { return 0; } + +static int pcie_port_runtime_idle(struct device *dev) +{ + /* Delay for a short while to prevent too frequent suspend/resume */ + pm_schedule_suspend(dev, 10); + return -EBUSY; +} #else #define pcie_port_runtime_suspend NULL #define pcie_port_runtime_resume NULL +#define pcie_port_runtime_idle NULL #endif static const struct dev_pm_ops pcie_portdrv_pm_ops = { @@ -155,6 +163,7 @@ static const struct dev_pm_ops pcie_portdrv_pm_ops = { .resume_noirq = pcie_port_resume_noirq, .runtime_suspend = pcie_port_runtime_suspend, .runtime_resume = pcie_port_runtime_resume, + .runtime_idle = pcie_port_runtime_idle, }; #define PCIE_PORTDRV_PM_OPS (&pcie_portdrv_pm_ops) -- cgit v1.2.3-70-g09d2