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From:   Zheyu Ma <zheyuma97@gmail.com>
Date:   Sat, 16 Jul 2022 16:50:08 +0800
Message-ID: <CAMhUBjkMyRP2iyMpovN7=GFP2SSpt+Na453RR6nNSBeyQR6oww@mail.gmail.com>
Subject: [BUG] power: supply: cw2015: Found a bug when removing the module
To:     t.schramm@manjaro.org, sre@kernel.org
Cc:     linux-pm@vger.kernel.org,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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Hello,

I found a bug in the cw2015 driver.

When I insmod the kernel module, I get the following log:

[  199.445154] cw2015 0-0010: probe
[  199.445447] cw2015 0-0010: No battery-profile found, using current
flash contents
[  199.447198] cw2015 0-0010: Can't check current battery profile, no
profile provided
[  199.448577] cw2015 0-0010: No monitored battery, some properties
will be missing
[  199.449556] i2c-core: driver [cw2015] registered
[  199.482970] cw2015 0-0010: No profile specified, continuing without profile
[  199.486086] cw2015 0-0010: Failed to get supply state: -19

And when I remove the module, I got the following warning:

[  200.470198] cw2015 0-0010: remove
[  200.471445] ------------[ cut here ]------------
[  200.472752] WARNING: CPU: 0 PID: 413 at drivers/base/devres.c:1058
devm_kfree+0x2a8/0x330
[  200.478314] RIP: 0010:devm_kfree+0x2a8/0x330
[  200.485019] Call Trace:
[  200.485226]  <TASK>
[  200.485405]  ? power_supply_put_battery_info+0xc2/0xe0
[  200.486169]  cw_bat_remove+0x89/0xa0 [cw2015_battery]
[  200.486570]  i2c_device_remove+0x181/0x1f0

I think the problem is that the driver fails to call the function
power_supply_get_battery_info(). However, when removing the module,
the driver executes power_supply_put_battery_info(), causing a
warning.

Since I'm not familiar with this driver, I will just report the bug to you.

regards,

Zheyu Ma