[PATCH 0/3] kselftest: Add test to report device log errors

["Nícolas F. R. A. Prado" <nfraprado@collabora.com>]

Log errors are the most widely used mechanism for reporting issues in
the kernel. When an error is logged using the device helpers, eg
dev_err(), it gets metadata attached that identifies the subsystem and
device where the message is coming from. This series makes use of that
metadata in a new test to report which devices logged errors.

The first two patches move a test and a helper script to keep things
organized before this new test is added in the third patch.

It is expected that there might be many false-positive error messages
throughout the drivers code which will be reported by this test. By
having this test in the first place and working through the results we
can address those occurrences by adjusting the loglevel of the messages
that turn out to not be real errors that require the user's attention.
It will also motivate additional error messages to be introduced in the
code to detect real errors where they turn out to be missing, since
it will be possible to detect said issues automatically.

As an example, below you can see the test result for
mt8192-asurada-spherion. The single standing issue has been investigated
and will be addressed in an EC firmware update [1]:

TAP version 13
1..1
 power_supply sbs-8-000b: driver failed to report `time_to_empty_now' property: -5
 power_supply sbs-8-000b: driver failed to report `time_to_empty_now' property: -5
 power_supply sbs-8-000b: driver failed to report `time_to_empty_now' property: -5
 power_supply sbs-8-000b: driver failed to report `time_to_empty_now' property: -5
 power_supply sbs-8-000b: driver failed to report `time_to_empty_now' property: -5
 power_supply sbs-8-000b: driver failed to report `time_to_empty_now' property: -5
 power_supply sbs-8-000b: driver failed to report `time_to_empty_now' property: -5
 power_supply sbs-8-000b: driver failed to report `time_to_empty_now' property: -5
 power_supply sbs-8-000b: driver failed to report `time_to_empty_now' property: -5
 power_supply sbs-8-000b: driver failed to report `time_to_empty_now' property: -5
 power_supply sbs-8-000b: driver failed to report `time_to_empty_now' property: -5
 power_supply sbs-8-000b: driver failed to report `time_to_empty_now' property: -5
 power_supply sbs-8-000b: driver failed to report `model_name' property: -6
 power_supply sbs-8-000b: driver failed to report `time_to_empty_now' property: -5
 power_supply sbs-8-000b: driver failed to report `energy_full_design' property: -6
 power_supply sbs-8-000b: driver failed to report `time_to_empty_now' property: -5
 power_supply sbs-8-000b: driver failed to report `time_to_empty_now' property: -5
 power_supply sbs-8-000b: driver failed to report `time_to_empty_now' property: -5
 power_supply sbs-8-000b: driver failed to report `time_to_empty_now' property: -5
 power_supply sbs-8-000b: driver failed to report `time_to_empty_now' property: -5
not ok 1 +power_supply:sbs-8-000b
 Totals: pass:0 fail:1 xfail:0 xpass:0 skip:0 error:0

[1] https://lore.kernel.org/all/cf4d8131-4b63-4c7a-9f27-5a0847c656c4@notapiano

Signed-off-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
---
Nícolas F. R. A. Prado (3):
      kselftest: devices: Move discoverable devices test to subdirectory
      kselftest: Move ksft helper module to common directory
      kselftest: devices: Add test to detect device error logs

 tools/testing/selftests/Makefile                   |  4 +-
 tools/testing/selftests/devices/Makefile           |  4 -
 .../testing/selftests/devices/error_logs/Makefile  |  3 +
 .../devices/error_logs/test_device_error_logs.py   | 85 ++++++++++++++++++++++
 tools/testing/selftests/devices/probe/Makefile     |  4 +
 .../{ => probe}/boards/Dell Inc.,XPS 13 9300.yaml  |  0
 .../{ => probe}/boards/google,spherion.yaml        |  0
 .../{ => probe}/test_discoverable_devices.py       |  7 +-
 .../selftests/{devices => kselftest}/ksft.py       |  0
 9 files changed, 101 insertions(+), 6 deletions(-)
---
base-commit: 7b4f2bc91c15fdcf948bb2d9741a9d7d54303f8d
change-id: 20240421-dev-err-log-selftest-28f5b8fc7cd0

Best regards,
-- 
Nícolas F. R. A. Prado <nfraprado@collabora.com>