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authorHans de Goede <hdegoede@redhat.com>2021-08-16 13:30:07 +0200
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2021-08-16 18:32:02 +0200
commitb25d5a1cd19896bb87b399d6e24896cf6f854d44 (patch)
treeb334601a18f581fea190dad06855bb7c4aecb6ad
parentLinux 5.14-rc6 (diff)
downloadlinux-b25d5a1cd19896bb87b399d6e24896cf6f854d44.tar.xz
linux-b25d5a1cd19896bb87b399d6e24896cf6f854d44.zip
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>
-rw-r--r--Documentation/ABI/testing/sysfs-platform_profile7
-rw-r--r--drivers/acpi/platform_profile.c3
2 files changed, 10 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-platform_profile b/Documentation/ABI/testing/sysfs-platform_profile
index dae9c8941905..baf1d125f9f8 100644
--- a/Documentation/ABI/testing/sysfs-platform_profile
+++ b/Documentation/ABI/testing/sysfs-platform_profile
@@ -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.
diff --git a/drivers/acpi/platform_profile.c b/drivers/acpi/platform_profile.c
index dd2fbf38e414..d418462ab791 100644
--- a/drivers/acpi/platform_profile.c
+++ b/drivers/acpi/platform_profile.c
@@ -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;