[PATCH v2] HID: hid-input: only ignore 0 battery events for digitizers

[PATCH v2] HID: hid-input: only ignore 0 battery events for digitizers

[Dmitry Torokhov]

Commit 581c4484769e ("HID: input: map digitizer battery usage") added
handling of battery events for digitizers (typically for batteries
presented in stylii). 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@xiaomi.com>
Fixes: 581c4484769e ("HID: input: map digitizer battery usage")
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---

v2: rebased on top of linux-next, dropped Tested-by: tag

 drivers/hid/hid-input.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c
index 5d7532d79d21..e56e7de53279 100644
--- a/drivers/hid/hid-input.c
+++ b/drivers/hid/hid-input.c
@@ -635,7 +635,10 @@ static void hidinput_update_battery(struct hid_device *dev, unsigned int usage,
 		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);
-- 
2.51.0.858.gf9c4a03a3a-goog


-- 
Dmitry

Re: [PATCH v2] HID: hid-input: only ignore 0 battery events for digitizers

[Jiri Kosina]

On Tue, 14 Oct 2025, Dmitry Torokhov wrote:

> Commit 581c4484769e ("HID: input: map digitizer battery usage") added
> handling of battery events for digitizers (typically for batteries
> presented in stylii). 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@xiaomi.com>
> Fixes: 581c4484769e ("HID: input: map digitizer battery usage")
> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
> ---
> 
> v2: rebased on top of linux-next, dropped Tested-by: tag

Applied, thanks!

-- 
Jiri Kosina
SUSE Labs

答复: [External Mail]Re: [PATCH v2] HID: hid-input: only ignore 0 battery events for digitizers

[卢国宏]

Hi Jiri!
Where can I find information about your commits? Is it "https://web.git.kernel.org/pub/scm/linux/kernel/git/hid/hid.git/log/?h=for-6.17/upstream-fixes"? So far, I haven't seen any information about this commit. I'll need this information when I submit this code to Google's GKI. Thank you!
________________________________________
发件人: Jiri Kosina <jikos@kernel.org>
发送时间: 2025年10月15日 23:15:18
收件人: Dmitry Torokhov
抄送: Benjamin Tissoires; 卢国宏; kenalba@google.com; linux-input@vger.kernel.org; linux-kernel@vger.kernel.org
主题: [External Mail]Re: [PATCH v2] HID: hid-input: only ignore 0 battery events for digitizers

[外部邮件] 此邮件来源于小米公司外部，请谨慎处理。若对邮件安全性存疑，请将邮件转发给misec@xiaomi.com进行反馈

On Tue, 14 Oct 2025, Dmitry Torokhov wrote:

> Commit 581c4484769e ("HID: input: map digitizer battery usage") added
> handling of battery events for digitizers (typically for batteries
> presented in stylii). 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@xiaomi.com>
> Fixes: 581c4484769e ("HID: input: map digitizer battery usage")
> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
> ---
>
> v2: rebased on top of linux-next, dropped Tested-by: tag

Applied, thanks!

--
Jiri Kosina
SUSE Labs

#/******本邮件及其附件含有小米公司的保密信息，仅限于发送给上面地址中列出的个人或群组。禁止任何其他人以任何形式使用（包括但不限于全部或部分地泄露、复制、或散发）本邮件中的信息。如果您错收了本邮件，请您立即电话或邮件通知发件人并删除本邮件！ This e-mail and its attachments contain confidential information from XIAOMI, which is intended only for the person or entity whose address is listed above. Any use of the information contained herein in any way (including, but not limited to, total or partial disclosure, reproduction, or dissemination) by persons other than the intended recipient(s) is prohibited. If you receive this e-mail in error, please notify the sender by phone or email immediately and delete it!******/#

Re: 答复: [External Mail]Re: [PATCH v2] HID: hid-input: only ignore 0 battery events for digitizers

[Jiri Kosina]

On Fri, 17 Oct 2025, 卢国宏 wrote:

> Where can I find information about your commits? Is it 
> "https://web.git.kernel.org/pub/scm/linux/kernel/git/hid/hid.git/log/?h=for-6.17/upstream-fixes"? 
> So far, I haven't seen any information about this commit. I'll need this 
> information when I submit this code to Google's GKI. Thank you!

The queue of fixes for 6.18 is at

	https://git.kernel.org/pub/scm/linux/kernel/git/hid/hid.git/log/?h=for-6.18/upstream-fixes

and it's just now on its way to Linus' tree:

	https://git.kernel.org/pub/scm/linux/kernel/git/hid/hid.git/log/?h=for-linus

-- 
Jiri Kosina
SUSE Labs

答复: 答复: [External Mail]Re: [PATCH v2] HID: hid-input: only ignore 0 battery events for digitizers

[卢国宏]

Thank you so much！
________________________________________
发件人: Jiri Kosina <jikos@kernel.org>
发送时间: 2025年10月17日 23:51:43
收件人: 卢国宏
抄送: Dmitry Torokhov; Benjamin Tissoires; kenalba@google.com; linux-input@vger.kernel.org; linux-kernel@vger.kernel.org; 李鹏
主题: Re: 答复: [External Mail]Re: [PATCH v2] HID: hid-input: only ignore 0 battery events for digitizers

[外部邮件] 此邮件来源于小米公司外部，请谨慎处理。若对邮件安全性存疑，请将邮件转发给misec@xiaomi.com进行反馈

On Fri, 17 Oct 2025, 卢国宏 wrote:

> Where can I find information about your commits? Is it
> "https://web.git.kernel.org/pub/scm/linux/kernel/git/hid/hid.git/log/?h=for-6.17/upstream-fixes"?
> So far, I haven't seen any information about this commit. I'll need this
> information when I submit this code to Google's GKI. Thank you!

The queue of fixes for 6.18 is at

        https://git.kernel.org/pub/scm/linux/kernel/git/hid/hid.git/log/?h=for-6.18/upstream-fixes

and it's just now on its way to Linus' tree:

        https://git.kernel.org/pub/scm/linux/kernel/git/hid/hid.git/log/?h=for-linus

--
Jiri Kosina
SUSE Labs

#/******本邮件及其附件含有小米公司的保密信息，仅限于发送给上面地址中列出的个人或群组。禁止任何其他人以任何形式使用（包括但不限于全部或部分地泄露、复制、或散发）本邮件中的信息。如果您错收了本邮件，请您立即电话或邮件通知发件人并删除本邮件！ This e-mail and its attachments contain confidential information from XIAOMI, which is intended only for the person or entity whose address is listed above. Any use of the information contained herein in any way (including, but not limited to, total or partial disclosure, reproduction, or dissemination) by persons other than the intended recipient(s) is prohibited. If you receive this e-mail in error, please notify the sender by phone or email immediately and delete it!******/#