Commit b25d5a1c authored Aug 16, 2021 by Hans de Goede Committed by Rafael J. Wysocki Aug 16, 2021

ACPI: platform-profile: call sysfs_notify() from platform_profile_store()



Drivers like thinkpad_acpi and ideapad_laptop call the
platform_profile_notify() helper when the profile is changed by hardware
(the embedded-controller/EC) in response to an EC handled hotkey.

This allows userspace to monitor for such changes by polling for POLLPRI
on the platform_profile sysfs file. But the profile can also be changed
underneath a userspace program monitoring it by anonther userspace program
storing a new value.

Add a sysfs_notify() call to platform_profile_store(), so that userspace
programs monitoring for changes also get notified in this case.

Also update the documentation to document that POLLPRI polling can be
used to watch for changes.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

parent 7c60610d

Documentation/ABI/testing/sysfs-platform_profile

+7 −0

Original line number	Diff line number	Diff line
		@@ -26,3 +26,10 @@ Contact: Hans de Goede <hdegoede@redhat.com>
		Description: Reading this file gives the current selected profile for this
		device. Writing this file with one of the strings from
		platform_profile_choices changes the profile to the new value.

		This file can be monitored for changes by polling for POLLPRI,
		POLLPRI will be signalled on any changes, independent of those
		changes coming from a userspace write; or coming from another
		source such as e.g. a hotkey triggered profile change handled
		either directly by the embedded-controller or fully handled
		inside the kernel.

drivers/acpi/platform_profile.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -106,6 +106,9 @@ static ssize_t platform_profile_store(struct device *dev,
		}

		err = cur_profile->profile_set(cur_profile, i);
		if (!err)
		sysfs_notify(acpi_kobj, NULL, "platform_profile");

		mutex_unlock(&profile_lock);
		if (err)
		return err;