答复: [External Mail][PATCH] HID: hid-input: only ignore 0 battery events for digitizers

From: 卢国宏
Date: Fri Oct 10 2025 - 06:44:09 EST


Thanks, Dmitry.

Hi Jiri Kosina, Benjamin Tissoires, please let me know once you've merged this patch into the kernel. Thanks!

________________________________________
发件人: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
发送时间: 2025年10月10日 14:12
收件人: Jiri Kosina; Benjamin Tissoires
抄送: 卢国宏; kenalba@xxxxxxxxxx; linux-input@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
主题: [External Mail][PATCH] HID: hid-input: only ignore 0 battery events for digitizers

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Commit 581c4484769e ("HID: input: map digitizer battery usage") added
handling of battery events for digitizers (typically for batteries
presented in styli). Digitizers typically report correct battery levels
only when stylus is actively touching the surface, and in other cases
they may report battery level of 0. To avoid confusing consumers of the
battery information the code was added to filer out reports with 0
battery levels.

However there exist other kinds of devices that may legitimately report
0 battery levels. Fix this by filtering out 0-level reports only for
digitizer usages, and continue reporting them for other kinds of devices
(Smart Batteries, etc).

Reported-by: 卢国宏 <luguohong@xxxxxxxxxx>
Tested-by: 卢国宏 <luguohong@xxxxxxxxxx>
Fixes: 581c4484769e ("HID: input: map digitizer battery usage")
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
---
drivers/hid/hid-input.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c
index ff1784b5c2a4..ba3f6655af9e 100644
--- a/drivers/hid/hid-input.c
+++ b/drivers/hid/hid-input.c
@@ -595,14 +595,18 @@ static void hidinput_cleanup_battery(struct hid_device *dev)
dev->battery = NULL;
}

-static void hidinput_update_battery(struct hid_device *dev, int value)
+static void hidinput_update_battery(struct hid_device *dev,
+ unsigned int usage, int value)
{
int capacity;

if (!dev->battery)
return;

- if (value == 0 || value < dev->battery_min || value > dev->battery_max)
+ if ((usage & HID_USAGE_PAGE) == HID_UP_DIGITIZER && value == 0)
+ return;
+
+ if (value < dev->battery_min || value > dev->battery_max)
return;

capacity = hidinput_scale_battery_capacity(dev, value);
@@ -1518,7 +1522,7 @@ void hidinput_hid_event(struct hid_device *hid, struct hid_field *field, struct
bool handled = hidinput_set_battery_charge_status(hid, usage->hid, value);

if (!handled)
- hidinput_update_battery(hid, value);
+ hidinput_update_battery(hid, usage->hid, value);

return;
}
--
2.51.0.740.g6adb054d12-goog


--
Dmitry
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