diff options
| author | Mario Limonciello <mario.limonciello@amd.com> | 2021-06-09 13:40:17 -0500 |
|---|---|---|
| committer | Christoph Hellwig <hch@lst.de> | 2021-06-16 05:14:59 +0200 |
| commit | 2744d7a0733503931b71c00d156119ced002f22c (patch) | |
| tree | 026a01cc99ca3d54b68d49a1f81f4a04707a4a03 /drivers/acpi/device_pm.c | |
| parent | e0d245e2230998e66dfda10fb8c413f29196eb1c (diff) | |
ACPI: Check StorageD3Enable _DSD property in ACPI code
Although first implemented for NVME, this check may be usable by
other drivers as well. Microsoft's specification explicitly mentions
that is may be usable by SATA and AHCI devices. Google also indicates
that they have used this with SDHCI in a downstream kernel tree that
a user can plug a storage device into.
Link: https://docs.microsoft.com/en-us/windows-hardware/design/component-guidelines/power-management-for-storage-hardware-devices-intro
Suggested-by: Keith Busch <kbusch@kernel.org>
CC: Shyam-sundar S-k <Shyam-sundar.S-k@amd.com>
CC: Alexander Deucher <Alexander.Deucher@amd.com>
CC: Rafael J. Wysocki <rjw@rjwysocki.net>
CC: Prike Liang <prike.liang@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'drivers/acpi/device_pm.c')
| -rw-r--r-- | drivers/acpi/device_pm.c | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/drivers/acpi/device_pm.c b/drivers/acpi/device_pm.c index d260bc1f3e6e..d76ab50c71dc 100644 --- a/drivers/acpi/device_pm.c +++ b/drivers/acpi/device_pm.c @@ -1340,4 +1340,33 @@ int acpi_dev_pm_attach(struct device *dev, bool power_on) return 1; } EXPORT_SYMBOL_GPL(acpi_dev_pm_attach); + +/** + * acpi_storage_d3 - Check if D3 should be used in the suspend path + * @dev: Device to check + * + * Return %true if the platform firmware wants @dev to be programmed + * into D3hot or D3cold (if supported) in the suspend path, or %false + * when there is no specific preference. On some platforms, if this + * hint is ignored, @dev may remain unresponsive after suspending the + * platform as a whole. + * + * Although the property has storage in the name it actually is + * applied to the PCIe slot and plugging in a non-storage device the + * same platform restrictions will likely apply. + */ +bool acpi_storage_d3(struct device *dev) +{ + struct acpi_device *adev = ACPI_COMPANION(dev); + u8 val; + + if (!adev) + return false; + if (fwnode_property_read_u8(acpi_fwnode_handle(adev), "StorageD3Enable", + &val)) + return false; + return val == 1; +} +EXPORT_SYMBOL_GPL(acpi_storage_d3); + #endif /* CONFIG_PM */ |