Re: [PATCH v1 2/3] ACPI: PM: Fix sharing of wakeup power resources

From: kernel test robot
Date: Tue Oct 19 2021 - 03:29:29 EST

Hi Rafael,

Thanks for your patch! Perhaps something to improve:

[auto build test WARNING on rafael-pm/linux-next]
[also build test WARNING on linux/master linus/master v5.15-rc5 next-20211015]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url: https://github.com/0day-ci/linux/commits/Rafael-J-Wysocki/ACPI-PM-Address-issues-related-to-managing-wakeup-power-resources/20211016-010527
base: https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git linux-next
config: x86_64-randconfig-c007-20211015 (attached as .config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 6069a6a5049497a32a50a49661c2f4169078bdba)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/0day-ci/linux/commit/5e93f177b80cbc9b9ee6ffc15ff9ad0ad23f2a7a
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Rafael-J-Wysocki/ACPI-PM-Address-issues-related-to-managing-wakeup-power-resources/20211016-010527
git checkout 5e93f177b80cbc9b9ee6ffc15ff9ad0ad23f2a7a
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 clang-analyzer

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@xxxxxxxxx>


clang-analyzer warnings:

>> drivers/acpi/power.c:739:2: warning: Undefined or garbage value returned to caller [clang-analyzer-core.uninitialized.UndefReturn]
return err;
^ ~~~
drivers/acpi/power.c:712:2: note: 'err' declared without an initial value
int err;
^~~~~~~
drivers/acpi/power.c:714:6: note: Assuming 'dev' is non-null
if (!dev || !dev->wakeup.flags.valid)
^~~~
drivers/acpi/power.c:714:6: note: Left side of '||' is false
drivers/acpi/power.c:714:14: note: Assuming field 'valid' is not equal to 0
if (!dev || !dev->wakeup.flags.valid)
^~~~~~~~~~~~~~~~~~~~~~~~
drivers/acpi/power.c:714:2: note: Taking false branch
if (!dev || !dev->wakeup.flags.valid)
^
drivers/acpi/power.c:719:6: note: Assuming the condition is true
if (dev->wakeup.prepare_count++)
^~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/acpi/power.c:719:2: note: Taking true branch
if (dev->wakeup.prepare_count++)
^
drivers/acpi/power.c:720:3: note: Control jumps to line 738
goto out;
^
drivers/acpi/power.c:739:2: note: Undefined or garbage value returned to caller
return err;
^ ~~~


vim +739 drivers/acpi/power.c

77e766099efc29 Rafael J. Wysocki 2008-07-07 703
^1da177e4c3f41 Linus Torvalds 2005-04-16 704 /*
^1da177e4c3f41 Linus Torvalds 2005-04-16 705 * Prepare a wakeup device, two steps (Ref ACPI 2.0:P229):
^1da177e4c3f41 Linus Torvalds 2005-04-16 706 * 1. Power on the power resources required for the wakeup device
77e766099efc29 Rafael J. Wysocki 2008-07-07 707 * 2. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
77e766099efc29 Rafael J. Wysocki 2008-07-07 708 * State Wake) for the device, if present
^1da177e4c3f41 Linus Torvalds 2005-04-16 709 */
77e766099efc29 Rafael J. Wysocki 2008-07-07 710 int acpi_enable_wakeup_device_power(struct acpi_device *dev, int sleep_state)
^1da177e4c3f41 Linus Torvalds 2005-04-16 711 {
5e93f177b80cbc Rafael J. Wysocki 2021-10-15 712 int err;
^1da177e4c3f41 Linus Torvalds 2005-04-16 713
^1da177e4c3f41 Linus Torvalds 2005-04-16 714 if (!dev || !dev->wakeup.flags.valid)
77e766099efc29 Rafael J. Wysocki 2008-07-07 715 return -EINVAL;
^1da177e4c3f41 Linus Torvalds 2005-04-16 716
9b83ccd2f14f64 Rafael J. Wysocki 2009-09-08 717 mutex_lock(&acpi_device_lock);
9b83ccd2f14f64 Rafael J. Wysocki 2009-09-08 718
9b83ccd2f14f64 Rafael J. Wysocki 2009-09-08 719 if (dev->wakeup.prepare_count++)
9b83ccd2f14f64 Rafael J. Wysocki 2009-09-08 720 goto out;
0af4b8c4fb3119 Rafael J. Wysocki 2008-07-07 721
5e93f177b80cbc Rafael J. Wysocki 2021-10-15 722 err = acpi_power_on_list(&dev->wakeup.resources);
993cbe595dda73 Rafael J. Wysocki 2013-01-17 723 if (err) {
5e93f177b80cbc Rafael J. Wysocki 2021-10-15 724 dev_err(&dev->dev, "Cannot turn on wakeup power resources\n");
^1da177e4c3f41 Linus Torvalds 2005-04-16 725 dev->wakeup.flags.valid = 0;
b5d667eb392ed9 Rafael J. Wysocki 2013-02-23 726 goto out;
b5d667eb392ed9 Rafael J. Wysocki 2013-02-23 727 }
5e93f177b80cbc Rafael J. Wysocki 2021-10-15 728
77e766099efc29 Rafael J. Wysocki 2008-07-07 729 /*
993cbe595dda73 Rafael J. Wysocki 2013-01-17 730 * Passing 3 as the third argument below means the device may be
993cbe595dda73 Rafael J. Wysocki 2013-01-17 731 * put into arbitrary power state afterward.
77e766099efc29 Rafael J. Wysocki 2008-07-07 732 */
0af4b8c4fb3119 Rafael J. Wysocki 2008-07-07 733 err = acpi_device_sleep_wake(dev, 1, sleep_state, 3);
9b83ccd2f14f64 Rafael J. Wysocki 2009-09-08 734 if (err)
9b83ccd2f14f64 Rafael J. Wysocki 2009-09-08 735 dev->wakeup.prepare_count = 0;
9b83ccd2f14f64 Rafael J. Wysocki 2009-09-08 736
9b83ccd2f14f64 Rafael J. Wysocki 2009-09-08 737 out:
9b83ccd2f14f64 Rafael J. Wysocki 2009-09-08 738 mutex_unlock(&acpi_device_lock);
0af4b8c4fb3119 Rafael J. Wysocki 2008-07-07 @739 return err;
^1da177e4c3f41 Linus Torvalds 2005-04-16 740 }
^1da177e4c3f41 Linus Torvalds 2005-04-16 741

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