drivers: spi: stm32: Fix race condition causing lockup in half-duplex mode #94957
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
kbidani
force-pushed
the
fix_spi_half_duplex
branch
from
7832b2d to
ab80caa
Compare
|
The following west manifest projects have changed revision in this Pull Request:
✅ All manifest checks OK Note: This message is automatically posted and updated by the Manifest GitHub Action. |
kbidani
force-pushed
the
fix_spi_half_duplex
branch
from
28b21a5 to
ab80caa
Compare
github-actions
bot
added
manifest-hal_stm32
DNM (manifest)
… mode This patch adds a check for the EOT (End Of Transfer) flag inside the polling loop in spi_stm32_half_duplex_switch_to_receive(). If EOT is set, the transfer is alreadycomplete and the loop is exited, preventing the lockup. Signed-off-by: Khaoula Bidani <[email protected]>
kbidani
force-pushed
the
fix_spi_half_duplex
branch
from
ab80caa to
cb0ca63
Compare
|
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
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Outdated suggestions cannot be applied.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.
A race condition could occur in half-duplex master mode when switching from TX to RX.
If a preemption happens immediately after starting the master transfer, the SPI hardware may complete the transfer before the polling loop is entered, causing the CSTART bit to be cleared and resulting in an infinite loop.
This patch adds a check for the EOT flag inside the polling loop in spi_stm32_half_duplex_switch_to_receive(). If EOT is set, the transfer is already complete and the loop is exited, preventing the lockup.
Issues: #94265