On 6/6/2023 1:21 PM, Rafael J. Wysocki wrote:
On Tue, Jun 6, 2023 at 6:23 PM Mario Limonciello
<mario.limonciello@xxxxxxx> wrote:
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);
s/val/enable/ ?
Then I don't have to remember that ACPI_REG_DISCONNECT is 0.
Sure, no problem.
<bikeshedding>
I would call this function something like
acpi_pci_config_space_access(), because technically it is about
allowing AML to access the PCI configuration space.
</bikeshedding>
Presumably platform_pci_config_space_access() below too.
That's fine by me, Bjorn?
+}
+
/* 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
