HID: hid-input: occasionally report stylus battery even if not changed

There are styluses that only report their battery status when they are
touching the touchscreen; additionally we currently suppress battery
reports if capacity has not changed. To help userspace recognize how long
ago the device reported battery status, let's send the change event through
if either capacity has changed, or at least 30 seconds have passed since
last report we've let through.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c
index 9770db624bfafca5c176075e09030cee41f0341c..b0db2a2ac15a7a8547930338c793ed90a7f47e09 100644 (file)
--- a/drivers/hid/hid-input.c
+++ b/drivers/hid/hid-input.c
@@ -534,9 +534,12 @@ static void hidinput_update_battery(struct hid_device *dev, int value)
        capacity = hidinput_scale_battery_capacity(dev, value);
 
        if (dev->battery_status != HID_BATTERY_REPORTED ||
-           capacity != dev->battery_capacity) {
+           capacity != dev->battery_capacity ||
+           ktime_after(ktime_get_coarse(), dev->battery_ratelimit_time)) {
                dev->battery_capacity = capacity;
                dev->battery_status = HID_BATTERY_REPORTED;
+               dev->battery_ratelimit_time =
+                       ktime_add_ms(ktime_get_coarse(), 30 * 1000);
                power_supply_changed(dev->battery);
        }
 }

diff --git a/include/linux/hid.h b/include/linux/hid.h
index 58684657960bf6dbd4c8039948273f10656ea46b..b079146850e6ef0e35ec82d0113b8f57e69d7d79 100644 (file)
--- a/include/linux/hid.h
+++ b/include/linux/hid.h
@@ -585,6 +585,7 @@ struct hid_device {                                                 /* device report descriptor */
        __s32 battery_report_id;
        enum hid_battery_status battery_status;
        bool battery_avoid_query;
+       ktime_t battery_ratelimit_time;
 #endif
 
        unsigned long status;                                           /* see STAT flags above */