From 4f9c1397e2e80e52b17ec4e39760caa807bd15c7 Mon Sep 17 00:00:00 2001 From: Huang Ying Date: Wed, 8 Aug 2012 09:07:38 +0800 Subject: [PATCH 1/5] 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/pci.c | 1 + drivers/pci/pcie/portdrv_pci.c | 5 +++++ 2 files changed, 6 insertions(+) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index f3ea977a5b1b..ab4bf5a4c2f1 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1941,6 +1941,7 @@ void pci_pm_init(struct pci_dev *dev) dev->pm_cap = pm; dev->d3_delay = PCI_PM_D3_WAIT; dev->d3cold_delay = PCI_PM_D3COLD_WAIT; + dev->d3cold_allowed = true; dev->d1_support = false; dev->d2_support = false; diff --git a/drivers/pci/pcie/portdrv_pci.c b/drivers/pci/pcie/portdrv_pci.c index 3a7eefcb270a..62f5a76c8f80 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); From ea8c88f13d9fb1d6b39a05bfa07ae076ca1c6803 Mon Sep 17 00:00:00 2001 From: Huang Ying Date: Wed, 8 Aug 2012 09:07:39 +0800 Subject: [PATCH 2/5] PCI/PM: Keep parent bridge active when probing device This patch fixes the following bug: http://marc.info/?l=linux-pci&m=134329923124234&w=2 The root cause of the bug is as follow. If a device is not bound with the corresponding driver, the device runtime PM will be disabled and the device will be put into suspended state. So that, the bridge/PCIe port connected to it may be put into suspended and low power state. When do probing for the device later, because the bridge/PCIe port connected to it is in low power state, the IO access to device may fail. To solve the issue, the bridge/PCIe port connected to the device is put into active state before probing. Reported-by: Bjorn Mork Signed-off-by: Huang Ying Signed-off-by: Bjorn Helgaas Reviewed-by: Rafael J. Wysocki --- drivers/pci/pci-driver.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index 5270f1a99328..d6fd6b6d9d4b 100644 --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -280,8 +280,12 @@ static long local_pci_probe(void *_ddi) { struct drv_dev_and_id *ddi = _ddi; struct device *dev = &ddi->dev->dev; + struct device *parent = dev->parent; int rc; + /* The parent bridge must be in active state when probing */ + if (parent) + pm_runtime_get_sync(parent); /* Unbound PCI devices are always set to disabled and suspended. * During probe, the device is set to enabled and active and the * usage count is incremented. If the driver supports runtime PM, @@ -298,6 +302,8 @@ static long local_pci_probe(void *_ddi) pm_runtime_set_suspended(dev); pm_runtime_put_noidle(dev); } + if (parent) + pm_runtime_put(parent); return rc; } From 3d8387efe1ad9eb5bfe8a2e58cdbd1b88b247eef Mon Sep 17 00:00:00 2001 From: Huang Ying Date: Wed, 15 Aug 2012 09:43:03 +0800 Subject: [PATCH 3/5] 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(+) diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index 6869009c7393..02d107b15281 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 62f5a76c8f80..e76b44777dbf 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) From 046c6531b60e8b9eabf47820a06161338a612167 Mon Sep 17 00:00:00 2001 From: Huang Ying Date: Wed, 8 Aug 2012 09:07:41 +0800 Subject: [PATCH 4/5] PCI/PM: Add ABI document for sysfs file d3cold_allowed This patch adds ABI document for the following sysfs file: /sys/bus/pci/devices/.../d3cold_allowed Signed-off-by: Huang Ying Signed-off-by: Bjorn Helgaas Acked-by: Rafael J. Wysocki --- Documentation/ABI/testing/sysfs-bus-pci | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci index 34f51100f029..dff1f48d252d 100644 --- a/Documentation/ABI/testing/sysfs-bus-pci +++ b/Documentation/ABI/testing/sysfs-bus-pci @@ -210,3 +210,15 @@ Users: firmware assigned instance number of the PCI device that can help in understanding the firmware intended order of the PCI device. + +What: /sys/bus/pci/devices/.../d3cold_allowed +Date: July 2012 +Contact: Huang Ying +Description: + d3cold_allowed is bit to control whether the corresponding PCI + device can be put into D3Cold state. If it is cleared, the + device will never be put into D3Cold state. If it is set, the + device may be put into D3Cold state if other requirements are + satisfied too. Reading this attribute will show the current + value of d3cold_allowed bit. Writing this attribute will set + the value of d3cold_allowed bit. From 0ff9514b579b4f2f3e6038cd961ce64c224c3c73 Mon Sep 17 00:00:00 2001 From: Bjorn Helgaas Date: Thu, 23 Aug 2012 10:53:08 -0600 Subject: [PATCH 5/5] PCI: Don't print anything while decoding is disabled If we try to print to the console device while its decoding is disabled, the system will hang. Reported-and-tested-by: Olof Johansson Signed-off-by: Bjorn Helgaas Acked-by: Olof Johansson --- drivers/pci/probe.c | 31 +++++++++++++++++-------------- 1 file changed, 17 insertions(+), 14 deletions(-) diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 6c143b4497ca..9f8a6b79a8ec 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -144,15 +144,13 @@ static inline unsigned long decode_bar(struct pci_dev *dev, u32 bar) case PCI_BASE_ADDRESS_MEM_TYPE_32: break; case PCI_BASE_ADDRESS_MEM_TYPE_1M: - dev_info(&dev->dev, "1M mem BAR treated as 32-bit BAR\n"); + /* 1M mem BAR treated as 32-bit BAR */ break; case PCI_BASE_ADDRESS_MEM_TYPE_64: flags |= IORESOURCE_MEM_64; break; default: - dev_warn(&dev->dev, - "mem unknown type %x treated as 32-bit BAR\n", - mem_type); + /* mem unknown type treated as 32-bit BAR */ break; } return flags; @@ -173,9 +171,11 @@ int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type, u32 l, sz, mask; u16 orig_cmd; struct pci_bus_region region; + bool bar_too_big = false, bar_disabled = false; mask = type ? PCI_ROM_ADDRESS_MASK : ~0; + /* No printks while decoding is disabled! */ if (!dev->mmio_always_on) { pci_read_config_word(dev, PCI_COMMAND, &orig_cmd); pci_write_config_word(dev, PCI_COMMAND, @@ -240,8 +240,7 @@ int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type, goto fail; if ((sizeof(resource_size_t) < 8) && (sz64 > 0x100000000ULL)) { - dev_err(&dev->dev, "reg %x: can't handle 64-bit BAR\n", - pos); + bar_too_big = true; goto fail; } @@ -252,12 +251,11 @@ int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type, region.start = 0; region.end = sz64; pcibios_bus_to_resource(dev, res, ®ion); + bar_disabled = true; } else { region.start = l64; region.end = l64 + sz64; pcibios_bus_to_resource(dev, res, ®ion); - dev_printk(KERN_DEBUG, &dev->dev, "reg %x: %pR\n", - pos, res); } } else { sz = pci_size(l, sz, mask); @@ -268,18 +266,23 @@ int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type, region.start = l; region.end = l + sz; pcibios_bus_to_resource(dev, res, ®ion); - - dev_printk(KERN_DEBUG, &dev->dev, "reg %x: %pR\n", pos, res); } - out: + goto out; + + +fail: + res->flags = 0; +out: if (!dev->mmio_always_on) pci_write_config_word(dev, PCI_COMMAND, orig_cmd); + if (bar_too_big) + dev_err(&dev->dev, "reg %x: can't handle 64-bit BAR\n", pos); + if (res->flags && !bar_disabled) + dev_printk(KERN_DEBUG, &dev->dev, "reg %x: %pR\n", pos, res); + return (res->flags & IORESOURCE_MEM_64) ? 1 : 0; - fail: - res->flags = 0; - goto out; } static void pci_read_bases(struct pci_dev *dev, unsigned int howmany, int rom)