From 50246dd41ccbcb47beb06d6c1d9355f6b7137a11 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Fri, 16 Jan 2009 08:14:51 -0800 Subject: Revert "PCI PM: Register power state of devices during initialization" This reverts commit 98e6e286d7b01deb7453b717aa38ebb69d6cefc0, as Yinghai Lu reports that it breaks kexec with at least the e1000 and e1000e drivers. The reason is that the shutdown sequence puts the hardware into D3 sleep, and the commit causes us to claim that it then is in D0 (running) state just because we don't understand the PM capabilities. Which then later makes "pci_set_power_state()" not do anything, and the device never wakes up properly and just returns 0xff to everything. Reported-by: Yinghai Lu Acked-by: From: Rafael J. Wysocki Cc: Jesse Barnes Signed-off-by: Linus Torvalds --- drivers/pci/pci.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) (limited to 'drivers/pci/pci.c') diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index c12f6c790698..e491fdedf705 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1260,15 +1260,14 @@ void pci_pm_init(struct pci_dev *dev) /* find PCI PM capability in list */ pm = pci_find_capability(dev, PCI_CAP_ID_PM); if (!pm) - goto Exit; - + return; /* Check device's ability to generate PME# */ pci_read_config_word(dev, pm + PCI_PM_PMC, &pmc); if ((pmc & PCI_PM_CAP_VER_MASK) > 3) { dev_err(&dev->dev, "unsupported PM cap regs version (%u)\n", pmc & PCI_PM_CAP_VER_MASK); - goto Exit; + return; } dev->pm_cap = pm; @@ -1307,9 +1306,6 @@ void pci_pm_init(struct pci_dev *dev) } else { dev->pme_support = 0; } - - Exit: - pci_update_current_state(dev, PCI_D0); } /** -- cgit v1.2.2 From aa8c6c93747f7b55fa11e1624fec8ca33763a805 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 16 Jan 2009 21:54:43 +0100 Subject: PCI PM: Restore standard config registers of all devices early There is a problem in our handling of suspend-resume of PCI devices that many of them have their standard config registers restored with interrupts enabled and they are put into the full power state with interrupts enabled as well. This may lead to the following scenario: * an interrupt vector is shared between two or more devices * one device is resumed earlier and generates an interrupt * the interrupt handler of another device tries to handle it and attempts to access the device the config space of which hasn't been restored yet and/or which still is in a low power state * the system crashes as a result To prevent this from happening we should restore the standard configuration registers of all devices with interrupts disabled and we should put them into the D0 power state right after that. Unfortunately, this cannot be done using the existing pci_set_power_state(), because it can sleep. Also, to do it we have to make sure that the config spaces of all devices were actually saved during suspend. Signed-off-by: Rafael J. Wysocki Acked-by: Linus Torvalds Signed-off-by: Jesse Barnes --- drivers/pci/pci.c | 63 +++++++++++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 57 insertions(+), 6 deletions(-) (limited to 'drivers/pci/pci.c') diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index e491fdedf705..17bd9325a245 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -22,7 +22,7 @@ #include /* isa_dma_bridge_buggy */ #include "pci.h" -unsigned int pci_pm_d3_delay = 10; +unsigned int pci_pm_d3_delay = PCI_PM_D3_WAIT; #ifdef CONFIG_PCI_DOMAINS int pci_domains_supported = 1; @@ -426,6 +426,7 @@ static inline int platform_pci_sleep_wake(struct pci_dev *dev, bool enable) * given PCI device * @dev: PCI device to handle. * @state: PCI power state (D0, D1, D2, D3hot) to put the device into. + * @wait: If 'true', wait for the device to change its power state * * RETURN VALUE: * -EINVAL if the requested state is invalid. @@ -435,7 +436,7 @@ static inline int platform_pci_sleep_wake(struct pci_dev *dev, bool enable) * 0 if device's power state has been successfully changed. */ static int -pci_raw_set_power_state(struct pci_dev *dev, pci_power_t state) +pci_raw_set_power_state(struct pci_dev *dev, pci_power_t state, bool wait) { u16 pmcsr; bool need_restore = false; @@ -480,8 +481,10 @@ pci_raw_set_power_state(struct pci_dev *dev, pci_power_t state) break; case PCI_UNKNOWN: /* Boot-up */ if ((pmcsr & PCI_PM_CTRL_STATE_MASK) == PCI_D3hot - && !(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET)) + && !(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET)) { need_restore = true; + wait = true; + } /* Fall-through: force to D0 */ default: pmcsr = 0; @@ -491,12 +494,15 @@ pci_raw_set_power_state(struct pci_dev *dev, pci_power_t state) /* enter specified state */ pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, pmcsr); + if (!wait) + return 0; + /* Mandatory power management transition delays */ /* see PCI PM 1.1 5.6.1 table 18 */ if (state == PCI_D3hot || dev->current_state == PCI_D3hot) msleep(pci_pm_d3_delay); else if (state == PCI_D2 || dev->current_state == PCI_D2) - udelay(200); + udelay(PCI_PM_D2_DELAY); dev->current_state = state; @@ -515,7 +521,7 @@ pci_raw_set_power_state(struct pci_dev *dev, pci_power_t state) if (need_restore) pci_restore_bars(dev); - if (dev->bus->self) + if (wait && dev->bus->self) pcie_aspm_pm_state_change(dev->bus->self); return 0; @@ -585,7 +591,7 @@ int pci_set_power_state(struct pci_dev *dev, pci_power_t state) if (state == PCI_D3hot && (dev->dev_flags & PCI_DEV_FLAGS_NO_D3)) return 0; - error = pci_raw_set_power_state(dev, state); + error = pci_raw_set_power_state(dev, state, true); if (state > PCI_D0 && platform_pci_power_manageable(dev)) { /* Allow the platform to finalize the transition */ @@ -730,6 +736,7 @@ pci_save_state(struct pci_dev *dev) /* XXX: 100% dword access ok here? */ for (i = 0; i < 16; i++) pci_read_config_dword(dev, i * 4,&dev->saved_config_space[i]); + dev->state_saved = true; if ((i = pci_save_pcie_state(dev)) != 0) return i; if ((i = pci_save_pcix_state(dev)) != 0) @@ -1373,6 +1380,50 @@ void pci_allocate_cap_save_buffers(struct pci_dev *dev) "unable to preallocate PCI-X save buffer\n"); } +/** + * pci_restore_standard_config - restore standard config registers of PCI device + * @dev: PCI device to handle + * + * This function assumes that the device's configuration space is accessible. + * If the device needs to be powered up, the function will wait for it to + * change the state. + */ +int pci_restore_standard_config(struct pci_dev *dev) +{ + pci_power_t prev_state; + int error; + + pci_restore_state(dev); + pci_update_current_state(dev, PCI_D0); + + prev_state = dev->current_state; + if (prev_state == PCI_D0) + return 0; + + error = pci_raw_set_power_state(dev, PCI_D0, false); + if (error) + return error; + + if (pci_is_bridge(dev)) { + if (prev_state > PCI_D1) + mdelay(PCI_PM_BUS_WAIT); + } else { + switch(prev_state) { + case PCI_D3cold: + case PCI_D3hot: + mdelay(pci_pm_d3_delay); + break; + case PCI_D2: + udelay(PCI_PM_D2_DELAY); + break; + } + } + + dev->current_state = PCI_D0; + + return 0; +} + /** * pci_enable_ari - enable ARI forwarding if hardware support it * @dev: the PCI device -- cgit v1.2.2