diff mbox

HID: input: throttle battery uevents

Message ID 20170810194756.GA15567@dtor-ws (mailing list archive)
State New, archived
Headers show

Commit Message

Dmitry Torokhov Aug. 10, 2017, 7:47 p.m. UTC 
The power_supply subsystem tends to emit uevent every time
power_supply_changed() is called, so we should call this API only when
battery strength reported by the device is actually different from the
previous readings, otherwise we'll drown the system in uevents.

Fixes: 581c4484769e ("HID: input: map digitizer battery usage")
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---
 drivers/hid/hid-input.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

Comments

Jiri Kosina Aug. 15, 2017, 8:56 a.m. UTC | #1 
On Thu, 10 Aug 2017, Dmitry Torokhov wrote:

> The power_supply subsystem tends to emit uevent every time
> power_supply_changed() is called, so we should call this API only when
> battery strength reported by the device is actually different from the
> previous readings, otherwise we'll drown the system in uevents.
> 
> Fixes: 581c4484769e ("HID: input: map digitizer battery usage")
> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Applied to for-4.14/battery. Thanks,
diff mbox

Patch

diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c
index 27d8442b017d..199f6a01fc62 100644
--- a/drivers/hid/hid-input.c
+++ b/drivers/hid/hid-input.c
@@ -520,15 +520,21 @@  static void hidinput_cleanup_battery(struct hid_device *dev)
 
 static void hidinput_update_battery(struct hid_device *dev, int value)
 {
+	int capacity;
+
 	if (!dev->battery)
 		return;
 
 	if (value == 0 || value < dev->battery_min || value > dev->battery_max)
 		return;
 
-	dev->battery_capacity = hidinput_scale_battery_capacity(dev, value);
-	dev->battery_reported = true;
-	power_supply_changed(dev->battery);
+	capacity = hidinput_scale_battery_capacity(dev, value);
+
+	if (!dev->battery_reported || capacity != dev->battery_capacity) {
+		dev->battery_capacity = capacity;
+		dev->battery_reported = true;
+		power_supply_changed(dev->battery);
+	}
 }
 #else  /* !CONFIG_HID_BATTERY_STRENGTH */
 static int hidinput_setup_battery(struct hid_device *dev, unsigned report_type,