Clearing UART TC Flag prevents deep sleep, so do not clear it #11688
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
The TC flag is used in function serial_is_tx_ongoing to check if there is an ongoing serial transmission. So this Flag must not be cleared at the end of the transmission, otherwise, serial_is_tx_ongoing will notify that TX is ongoing. The impact is that it may prevent deep sleep to be entered. Also there is no need to clear this flag at the end of the transaction because it will be cleared automatically by HW when a new transmission starts.
kjbracey
approved these changes
Oct 15, 2019
jeromecoutant
approved these changes
Oct 15, 2019
|
CI started |
Test run: SUCCESSSummary: 12 of 12 test jobs passed |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Description
Fix to address #11361
The TC flag is used in function serial_is_tx_ongoing to check if there is
an ongoing serial transmission. So this Flag must not be cleared at the
end of the transmission, otherwise, serial_is_tx_ongoing will notify that
TX is ongoing.
The impact is that it may prevent deep sleep to be entered.
Also there is no need to clear this flag at the end of the transaction
because it will be cleared automatically by HW when a new transmission
starts.
Pull request type
Reviewers
@jeromecoutant please review
@ua1arn please verify if that fixes your issue
Release Notes
Note that the issue has been reproduced using the Serial Async API.
The fix solves the issues reusing the similar test case as provided in the issue description.
I am not sure if there is an automated test that can be used to make sure there is no regression around Serial Async API.