ASMedia PCIe GPIO controllers fail functional tests after returning from suspend (S3 or s2idle). This is because the BIOS checks whether the OSPM has called the `_REG` method to determine whether it can interact with the OperationRegion assigned to the device. As described in 6.5.4 in the APCI spec, `_REG` is used to inform the AML code on the availability of an operation region. To fix this issue, call acpi_evaluate_reg() when saving and restoring the state of PCI devices. Link: https://uefi.org/htmlspecs/ACPI_Spec_6_4_html/06_Device_Configuration/Device_Configuration.html#reg-region Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx> --- v1->v2: * Handle case of no CONFIG_ACPI * Rename function * Update commit message * Move ACPI calling code into pci-acpi.c instead * Cite the ACPI spec --- drivers/pci/pci-acpi.c | 10 ++++++++++ drivers/pci/pci.c | 14 ++++++++++++++ drivers/pci/pci.h | 2 ++ 3 files changed, 26 insertions(+) diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c index 1698205dd73c..abc8bcfc2c71 100644 --- a/drivers/pci/pci-acpi.c +++ b/drivers/pci/pci-acpi.c @@ -1209,6 +1209,16 @@ void acpi_pci_remove_bus(struct pci_bus *bus) acpi_pci_slot_remove(bus); } +void acpi_pci_set_register_access(struct pci_dev *dev, bool enable) +{ + int val = enable ? ACPI_REG_CONNECT : ACPI_REG_DISCONNECT; + int ret = acpi_evaluate_reg(ACPI_HANDLE(&dev->dev), + ACPI_ADR_SPACE_PCI_CONFIG, val); + if (ret) + pci_dbg(dev, "ACPI _REG %s evaluation failed (%d)\n", + val ? "connect" : "disconnect", ret); +} + /* ACPI bus type */ diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index e38c2f6eebd4..b2f1f603ec62 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1068,6 +1068,14 @@ static inline bool platform_pci_bridge_d3(struct pci_dev *dev) return acpi_pci_bridge_d3(dev); } +static inline void platform_set_register_access(struct pci_dev *dev, bool en) +{ + if (pci_use_mid_pm()) + return; + + acpi_pci_set_register_access(dev, en); +} + /** * pci_update_current_state - Read power state of given device and cache it * @dev: PCI device to handle. @@ -1645,6 +1653,9 @@ static void pci_restore_ltr_state(struct pci_dev *dev) int pci_save_state(struct pci_dev *dev) { int i; + + platform_set_register_access(dev, false); + /* XXX: 100% dword access ok here? */ for (i = 0; i < 16; i++) { pci_read_config_dword(dev, i * 4, &dev->saved_config_space[i]); @@ -1790,6 +1801,8 @@ void pci_restore_state(struct pci_dev *dev) pci_enable_acs(dev); pci_restore_iov_state(dev); + platform_set_register_access(dev, true); + dev->state_saved = false; } EXPORT_SYMBOL(pci_restore_state); @@ -3203,6 +3216,7 @@ void pci_pm_init(struct pci_dev *dev) pci_read_config_word(dev, PCI_STATUS, &status); if (status & PCI_STATUS_IMM_READY) dev->imm_ready = 1; + platform_set_register_access(dev, true); } static unsigned long pci_ea_flags(struct pci_dev *dev, u8 prop) diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index ffccb03933e2..78961505aae2 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -703,6 +703,7 @@ void acpi_pci_refresh_power_state(struct pci_dev *dev); int acpi_pci_wakeup(struct pci_dev *dev, bool enable); bool acpi_pci_need_resume(struct pci_dev *dev); pci_power_t acpi_pci_choose_state(struct pci_dev *pdev); +void acpi_pci_set_register_access(struct pci_dev *dev, bool enable); #else static inline int pci_dev_acpi_reset(struct pci_dev *dev, bool probe) { @@ -742,6 +743,7 @@ static inline pci_power_t acpi_pci_choose_state(struct pci_dev *pdev) { return PCI_POWER_ERROR; } +static inline void acpi_pci_set_register_access(struct pci_dev *dev, bool enable) {} #endif #ifdef CONFIG_PCIEASPM -- 2.34.1
