NRF52: serial_api: Use polling for putc #8048
Merged
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
There are scenarios where putc is called within a critical section, e.g to log ASSERTs in early initialization code. The interrupts being disabled here prevents the handlers for the UARTE from executing. This breaks the tx_in_progress flag based approach. The tx_in_progress never gets reset. Poll on the TXDRDY instead. It can be recreated with a simple program as shown here: *************** Current Behavior **************** ++ MbedOS Error Info ++ Error Status: 0x80FF0100 Code: 256 Module: 255 Error Message: F ************** With Fix ************************* ++ MbedOS Error Info ++ Error Status: 0x80FF0100 Code: 256 Module: 255 Error Message: Fatal Run-time error Location: 0x2C0A9 Error Value: 0x0 Current Thread: Id: 0x20005520 Entry: 0x30EBF StackSize: 0x1000 StackMem: 0x20004520 SP: 0x20005490 For more info, visit: https://armmbed.github.io/mbedos-error/?error=0x80FF0100 -- MbedOS Error Info -- nrf failure at .\main.cpp:22 ***************************************************
kjbracey
approved these changes
Sep 12, 2018
|
This change allows the sleep profiler to work... otherwise it will hang as it tries to do a print in a critical section as discussed here: #8084 |
c1728p9
approved these changes
Sep 17, 2018
There was a problem hiding this comment.
Adding @marcuschangarm since he worked on a lot of this code.
0xc0170
approved these changes
Sep 21, 2018
|
/morph build |
Build : SUCCESSBuild number : 3197 Triggering tests/morph test |
Exporter Build : SUCCESSBuild number : 2789 |
Test : SUCCESSBuild number : 2997 |
RobMeades
added a commit
to u-blox/mbed-os
that referenced
this pull request
Oct 15, 2018
… occasional "serial port stuck" issue.
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.
There are scenarios where putc is called within a critical section, e.g
to log ASSERTs in early initialization code. The interrupts being
disabled here prevents the handlers for the UARTE from executing.
This breaks the tx_in_progress flag based approach. The tx_in_progress
never gets reset. Poll on the TXDRDY instead.
It can be recreated with a simple program as shown here: https://goo.gl/kLiAQF
*************** Current Behavior ****************
++ MbedOS Error Info ++
Error Status: 0x80FF0100 Code: 256 Module: 255
Error Message: F
************** With Fix *************************
++ MbedOS Error Info ++
Error Status: 0x80FF0100 Code: 256 Module: 255
Error Message: Fatal Run-time error
Location: 0x2C0A9
Error Value: 0x0
Current Thread: Id: 0x20005520 Entry: 0x30EBF StackSize: 0x1000 StackMem: 0x20004520 SP: 0x20005490
For more info, visit: https://armmbed.github.io/mbedos-error/?error=0x80FF0100
-- MbedOS Error Info --
nrf failure at .\main.cpp:22
Description
When in a critical section, the interrupts are disabled and hence the tx_in_progress will never get cleared
leading to an infinite wait.
Pull request type
Fix UART TX that is based on tx_in_progress variable. This may not get reset when in critical section.
Hence use polling.