]> git.ipfire.org Git - thirdparty/kernel/stable.git/commit
misc: lis3lv02d_i2c: Fix regulators getting en-/dis-abled twice on suspend/resume
authorHans de Goede <hdegoede@redhat.com>
Tue, 20 Feb 2024 19:00:35 +0000 (20:00 +0100)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 3 Apr 2024 13:11:39 +0000 (15:11 +0200)
commitf6df761182fc953907b18aba5049fc2a044ecb45
treeb3549f439a155afd8abe9194abc92e703d5f3c76
parent0f1d33b79ac7cd0c7dce1d67e08709dbcc16d11c
misc: lis3lv02d_i2c: Fix regulators getting en-/dis-abled twice on suspend/resume

commit ac3e0384073b2408d6cb0d972fee9fcc3776053d upstream.

When not configured for wakeup lis3lv02d_i2c_suspend() will call
lis3lv02d_poweroff() even if the device has already been turned off
by the runtime-suspend handler and if configured for wakeup and
the device is runtime-suspended at this point then it is not turned
back on to serve as a wakeup source.

Before commit b1b9f7a49440 ("misc: lis3lv02d_i2c: Add missing setting
of the reg_ctrl callback"), lis3lv02d_poweroff() failed to disable
the regulators which as a side effect made calling poweroff() twice ok.

Now that poweroff() correctly disables the regulators, doing this twice
triggers a WARN() in the regulator core:

unbalanced disables for regulator-dummy
WARNING: CPU: 1 PID: 92 at drivers/regulator/core.c:2999 _regulator_disable
...

Fix lis3lv02d_i2c_suspend() to not call poweroff() a second time if
already runtime-suspended and add a poweron() call when necessary to
make wakeup work.

lis3lv02d_i2c_resume() has similar issues, with an added weirness that
it always powers on the device if it is runtime suspended, after which
the first runtime-resume will call poweron() again, causing the enabled
count for the regulator to increase by 1 every suspend/resume. These
unbalanced regulator_enable() calls cause the regulator to never
be turned off and trigger the following WARN() on driver unbind:

WARNING: CPU: 1 PID: 1724 at drivers/regulator/core.c:2396 _regulator_put

Fix this by making lis3lv02d_i2c_resume() mirror the new suspend().

Fixes: b1b9f7a49440 ("misc: lis3lv02d_i2c: Add missing setting of the reg_ctrl callback")
Reported-by: Paul Menzel <pmenzel@molgen.mpg.de>
Closes: https://lore.kernel.org/regressions/5fc6da74-af0a-4aac-b4d5-a000b39a63a5@molgen.mpg.de/
Cc: stable@vger.kernel.org
Cc: regressions@lists.linux.dev
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Tested-by: Paul Menzel <pmenzel@molgen.mpg.de> # Dell XPS 15 7590
Reviewed-by: Paul Menzel <pmenzel@molgen.mpg.de>
Link: https://lore.kernel.org/r/20240220190035.53402-1-hdegoede@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/misc/lis3lv02d/lis3lv02d_i2c.c