ACPI: Export FADT pm_profile integer value to userspace
There are a lot userspace approaches to detect the usage of the
platform (laptop, workstation, server, ...) and adjust kernel tunables
accordingly (io/process scheduler, power management, ...).
These approaches need constant maintaining and are ugly to implement
(detect PCMCIA controller -> laptop,
does not work on recent systems anymore, ...)
On ACPI systems there is an easy and reliable way (if implemented
in BIOS and most recent platforms have this value set).
-> export it to userspace.
Signed-off-by: Thomas Renninger <trenn@suse.de>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/acpi/sysfs.c b/drivers/acpi/sysfs.c
index c538d0e..9f66181 100644
--- a/drivers/acpi/sysfs.c
+++ b/drivers/acpi/sysfs.c
@@ -706,11 +706,23 @@
return;
}
+static ssize_t
+acpi_show_profile(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ return sprintf(buf, "%d\n", acpi_gbl_FADT.preferred_profile);
+}
+
+static const struct device_attribute pm_profile_attr =
+ __ATTR(pm_profile, S_IRUGO, acpi_show_profile, NULL);
+
int __init acpi_sysfs_init(void)
{
int result;
result = acpi_tables_sysfs_init();
-
+ if (result)
+ return result;
+ result = sysfs_create_file(acpi_kobj, &pm_profile_attr.attr);
return result;
}