samples: bluetooth: Fix bt_le_scan_stop() error checking in central_multilink sample

[ramana-g-123]

Fixes #84187
The logic in central_multilink example outputs "Scanning successfully stopped" when the stop call has failed as the bt_le_scan_stop() call returns 0 when successful and error when unsuccessful

[github-actions]

Hello @ramana-g-123, and thank you very much for your first pull request to the Zephyr project!
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[jhedberg]

@ramana-g-123 thanks for the pull request! The change itself looks great, however please fix the commit message to be compliant with Zephyr requirements:

• Add a prefix to the subject. This can be e.g. "samples: bluetooth: ..."
• Remove the issue reference from the subject and instead have a short version of what the actual change is there, e.g. "samples: bluetooth: Fix bt_le_scan_stop() error checking"
• Add a Signed-off-by line. git will do this automatically for you when you pass -s to git commit.
• Add the issue reference to the PR description. GitHub recognizes this in the format "Fixes #...." and will link the two automatically together then.

[sjanc]

Hmm isn't the check correct but printed error message is wrong?

[Thalley]

If bt_le_scan_stop returns 0 it means that it was stopped :) Looks right to me

[jhedberg]

Looking at the more general flow of the function, I believe the purpose is to proceed to the bt_conn_le_create() step when scanning was stopped, so we shouldn't return from the function in a success case. So it does seem like @sjanc is right, i.e. the log message is wrong. Since the function has an err variable, I'd also take advantage of it in the same go:

err = bt_le_scan_stop();
if (err != 0) {
	printk("Failed to stop scanning (err %d)\n", err);
	return;
}

@ramana-g-123 can you update the PR accordingly? Thanks.

[cvinayak]

Agree with @sjanc and @jhedberg, on failure to stop scanning the control should not proceed further to setup a connection. Hence, it is the message that is incorrect.

@ramana-g-123 Thank you for noticing the issue.

[jhedberg]

Looking at the more general flow of the function, I believe the purpose is to proceed to the bt_conn_le_create() step when scanning was stopped, so we shouldn't return from the function in a success case. So it does seem like @sjanc is right, i.e. the log message is wrong. Since the function has an err variable, I'd also take advantage of it in the same go:

err = bt_le_scan_stop();
if (err != 0) {
	printk("Failed to stop scanning (err %d)\n", err);
	return;
}

@ramana-g-123 can you update the PR accordingly? Thanks.

[cvinayak]

Agree with @sjanc and @jhedberg, on failure to stop scanning the control should not proceed further to setup a connection. Hence, it is the message that is incorrect.

@ramana-g-123 Thank you for noticing the issue.

[cvinayak]

@ramana-g-123 thanks for the pull request! The change itself looks great, however please fix the commit message to be compliant with Zephyr requirements:

* Add a prefix to the subject. This can be e.g. "samples: bluetooth: ..."

* Remove the issue reference from the subject and instead have a short version of what the actual change is there, e.g. "samples: bluetooth: Fix bt_le_scan_stop() error checking"

* Add a Signed-off-by line. git will do this automatically for you when you pass `-s` to `git commit`.

* Add the issue reference to the PR description. GitHub recognizes this in the format "Fixes #...." and will link the two automatically together then.

Code looks good now... @ramana-g-123 please follow above suggestion to have single commit in this PR.

[jhedberg]

@ramana-g-123 you still need a commit message body. You can find more info here: https://docs.zephyrproject.org/latest/contribute/guidelines.html#commit-message-guidelines

[jhedberg]

@ramana-g-123 and also note this failure: UC5 Commit title exceeds max length (84>75). FWIW, you can run the compliance script yourself prior to pushing, if you want to save some time: scripts/ci/check_compliance.py

[jhedberg]

@ramana-g-123 the commit message still isn't compliant, causing the Compliance check to fail: "Commit message body line exceeds max length (160>75)". Once that's fixed I think we can merge it.

[jhedberg]

@ramana-g-123 you don't need to close/re-open pull requests like this. Just a force-push is enough.

[ramana-g-123]

Hey @jhedberg , sorry for the previous commit I was unable to run compliance_checks.py with the following issue even after installing all the packages needed using requirements.txt

  File "C:\Zephyr_RTOS\zephyr\scripts\ci\check_compliance.py", line 29, in <module>
    import magic
  File "C:\Zephyr_RTOS\zephyr\myenv\Lib\site-packages\magic\__init__.py", line 209, in <module>
    libmagic = loader.load_lib()
  File "C:\Zephyr_RTOS\zephyr\myenv\Lib\site-packages\magic\loader.py", line 49, in load_lib
    raise ImportError('failed to find libmagic.  Check your installation')
ImportError: failed to find libmagic.  Check your installation

[Thalley]

Hey @jhedberg , sorry for the previous commit I was unable to run compliance_checks.py with the following issue even after installing all the packages needed using requirements.txt

  File "C:\Zephyr_RTOS\zephyr\scripts\ci\check_compliance.py", line 29, in <module>
    import magic
  File "C:\Zephyr_RTOS\zephyr\myenv\Lib\site-packages\magic\__init__.py", line 209, in <module>
    libmagic = loader.load_lib()
  File "C:\Zephyr_RTOS\zephyr\myenv\Lib\site-packages\magic\loader.py", line 49, in load_lib
    raise ImportError('failed to find libmagic.  Check your installation')
ImportError: failed to find libmagic.  Check your installation

@ramana-g-123 did you install the requirements-compliance.txt as well?