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authorDmitry Torokhov <dmitry.torokhov@gmail.com>2017-08-10 12:47:56 -0700
committerJiri Kosina <jkosina@suse.cz>2017-08-15 10:56:03 +0200
commit0152b29c89650654abf4f0e96bbf2566b85ae55d (patch)
tree2450b3a252aa347795e26390d513a60eaf6334e5 /drivers/hid/hid-input.c
parent0922386538f9da8f242b1d52b5538bf9b8ddded5 (diff)
downloadlinux-0152b29c89650654abf4f0e96bbf2566b85ae55d.tar.gz
HID: input: throttle battery uevents
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>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Diffstat (limited to 'drivers/hid/hid-input.c')
-rw-r--r--drivers/hid/hid-input.c12
1 files changed, 9 insertions, 3 deletions
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,