From e13cdbd71fe12c4e191b737c4a3dbfdb4b2de03b Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Mon, 5 Oct 2009 00:48:40 +0200 Subject: PCI PM: Read device power state from register after updating it After attempting to change the power state of a PCI device pci_raw_set_power_state() doesn't check if the value it wrote into the device's PCI_PM_CTRL register has been stored in there, but unconditionally modifies the device's current_state field to reflect the change. This may cause problems to happen if the power state of the device hasn't been changed in fact, because it will make the PCI PM core make a wrong assumption. To prevent such situations from happening modify pci_raw_set_power_state() so that it reads the device's PCI_PM_CTRL register after writing into it and uses the value read from the register to update the device's current_state field. Also make it print a message saying that the device refused to change its power state as requested (returning an error code in such cases would cause suspend regressions to appear on some systems, where device drivers' suspend routines return error codes if pci_set_power_state() fails). Reviewed-by: Alex Chiang Signed-off-by: Rafael J. Wysocki Signed-off-by: Jesse Barnes --- drivers/pci/pci.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'drivers/pci/pci.c') diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 6edecff0b419..6e1da5aa7bb9 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -513,7 +513,11 @@ static int pci_raw_set_power_state(struct pci_dev *dev, pci_power_t state) else if (state == PCI_D2 || dev->current_state == PCI_D2) udelay(PCI_PM_D2_DELAY); - dev->current_state = state; + pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr); + dev->current_state = (pmcsr & PCI_PM_CTRL_STATE_MASK); + if (dev->current_state != state && printk_ratelimit()) + dev_info(&dev->dev, "Refused to change power state, " + "currently in D%d\n", dev->current_state); /* According to section 5.4.1 of the "PCI BUS POWER MANAGEMENT * INTERFACE SPECIFICATION, REV. 1.2", a device transitioning -- cgit v1.2.2 From 19eea630f7c56038dd80fe2f6910c78655bf29c8 Mon Sep 17 00:00:00 2001 From: Randy Dunlap Date: Thu, 17 Sep 2009 15:28:22 -0700 Subject: PCI: pci.c: fix kernel-doc notation Fix kernel-doc notation (& warnings) in pci/pci.c. Signed-off-by: Randy Dunlap Signed-off-by: Jesse Barnes --- drivers/pci/pci.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'drivers/pci/pci.c') diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 6e1da5aa7bb9..3835871f4832 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -2546,10 +2546,10 @@ int pci_resource_bar(struct pci_dev *dev, int resno, enum pci_bar_type *type) /** * pci_set_vga_state - set VGA decode state on device and parents if requested - * @dev the PCI device - * @decode - true = enable decoding, false = disable decoding - * @command_bits PCI_COMMAND_IO and/or PCI_COMMAND_MEMORY - * @change_bridge - traverse ancestors and change bridges + * @dev: the PCI device + * @decode: true = enable decoding, false = disable decoding + * @command_bits: PCI_COMMAND_IO and/or PCI_COMMAND_MEMORY + * @change_bridge: traverse ancestors and change bridges */ int pci_set_vga_state(struct pci_dev *dev, bool decode, unsigned int command_bits, bool change_bridge) -- cgit v1.2.2