linux/drivers/misc/lis3lv02d
Hans de Goede ac3e038407 misc: lis3lv02d_i2c: Fix regulators getting en-/dis-abled twice on suspend/resume
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 b1b9f7a494 ("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: b1b9f7a494 ("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>
2024-03-04 07:59:43 +01:00
..
Kconfig Merge 5.2-rc4 into char-misc-next 2019-06-09 09:11:21 +02:00
lis3lv02d_i2c.c misc: lis3lv02d_i2c: Fix regulators getting en-/dis-abled twice on suspend/resume 2024-03-04 07:59:43 +01:00
lis3lv02d_spi.c spi: make remove callback a void function 2022-02-09 13:00:45 +00:00
lis3lv02d.c misc: Explicitly include correct DT includes 2023-08-04 15:39:04 +02:00
lis3lv02d.h misc: lis3lv02d: Make lis3lv02d_remove_fs() return void 2021-10-13 14:35:20 +02:00
Makefile treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00