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>
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.
}
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;