From: Hans de Goede <hdegoede@redhat.com>
To: "Rafael J . Wysocki" <rjw@rjwysocki.net>
Cc: Hans de Goede <hdegoede@redhat.com>,
Mark Pearson <markpearson@lenovo.com>,
Len Brown <lenb@kernel.org>, Andy Shevchenko <andy@kernel.org>,
"Luke D . Jones" <luke@ljones.dev>,
linux-acpi@vger.kernel.org, platform-driver-x86@vger.kernel.org
Subject: [PATCH] ACPI: platform-profile: call sysfs_notify() from platform_profile_store()
Date: Mon, 16 Aug 2021 13:30:07 +0200 [thread overview]
Message-ID: <20210816113007.88902-1-hdegoede@redhat.com> (raw)
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>
---
Documentation/ABI/testing/sysfs-platform_profile | 7 +++++++
drivers/acpi/platform_profile.c | 3 +++
2 files changed, 10 insertions(+)
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;
--
2.31.1
next reply other threads:[~2021-08-16 11:30 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-16 11:30 Hans de Goede [this message]
2021-08-16 16:33 ` [PATCH] ACPI: platform-profile: call sysfs_notify() from platform_profile_store() Rafael J. Wysocki
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