| Message ID | cadbd4eb-40bb-1fa8-1e00-dc95dab62295@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | PCI: Forbid RPM on ACPI systems before 5.0 only | expand |
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 428afd459..26e3a500c 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -3101,7 +3101,12 @@ void pci_pm_init(struct pci_dev *dev) u16 status; u16 pmc; - pm_runtime_forbid(&dev->dev); +#ifdef CONFIG_ACPI + /* Some early ACPI PM implementations conflict with RPM. */ + if (acpi_gbl_FADT.header.revision > 0 && + acpi_gbl_FADT.header.revision < 5) + pm_runtime_forbid(&dev->dev); +#endif pm_runtime_set_active(&dev->dev); pm_runtime_enable(&dev->dev); device_enable_async_suspend(&dev->dev);
Currently PCI core forbids RPM and requires opt-in from userspace, apart from few drivers calling pm_runtime_allow(). Reason is that some early ACPI PM implementations conflict with RPM, see [0]. Note that as of today pm_runtime_forbid() is also called for non-ACPI systems. Maybe it's time to allow RPM per default for non-ACPI systems and recent enough ACPI versions. Let's allow RPM from ACPI 5.0 which was published in 2011. [0] https://lkml.org/lkml/2020/11/17/1548 Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> --- drivers/pci/pci.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)