drivers/mtd: Optimizations for RRAM/MRAM Compatibility and Erase Logic Robustness #17845
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
When there's no erase function for mtd, we decide if we need erase_buffer based on this: 1. If we've got bad block marking, we still need the erase buffer. If a write fails, it's used to read back the entire bad block's contents before writing to a new block. 2. If we don't have bad block marking, the erase buffer isn't needed and can be skipped. Signed-off-by: jingfei <[email protected]>
Accessing RRAM/MRAM from the FTL interface can cause errors because RRAM lacks an erase interface. To make RRAM/MRAM compatible with FTL, the FTL layer erase interface needs to be modified. Signed-off-by: jingfei <[email protected]>
Since there is a storage device like RRAM that doesn't require erasing, the MTD erase function may not exist. Here, we should first check whether the erase interface exists before performing the erasing operation. Signed-off-by: jingfei <[email protected]>
the MTD ERASE interface has inconsistent return values. Some implementations return the number of erased sectors, while others return OK (0). It is currently recommended to uniformly treat ERASE success as OK. Therefore, the logic for judging the return value of MTD_ERASE in the FTL erase interface should be changed to check if it is greater than 0. Signed-off-by: jingfei <[email protected]>
jingfei195887
requested review from
Donny9,
xiaoxiang781216 and
yamt
as code owners
github-actions
bot
added
Area: Drivers
There was a problem hiding this comment.
Pull request overview
This PR adds support for non-erase-required storage devices (RRAM/MRAM) to the FTL and MTD subsystems by making erase operations optional and improving error handling for devices that don't support erase operations.
Changes:
- Modified MTD partition layer to conditionally assign erase function based on parent device capability
- Enhanced FTL erase function to handle -ENOSYS return code for devices without erase support
- Added fast path in FTL flush function for devices without erase capability and bad block management
Reviewed changes
Copilot reviewed 2 out of 2 changed files in this pull request and generated 3 comments.
| File | Description |
|---|---|
| drivers/mtd/mtd_partition.c | Conditionally assigns erase function pointer only if parent MTD device supports erase |
| drivers/mtd/ftl.c | Adds -ENOSYS handling to ftl_mtd_erase and implements direct write path for non-erase devices in ftl_flush |
💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.
xiaoxiang781216
approved these changes
Jan 12, 2026
jerpelea
changed the title
jerpelea
approved these changes
Jan 14, 2026
xiaoxiang781216
approved these changes
Jan 14, 2026
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
3 participants
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.
Summary
This PR contains a series of optimizations and compatibility adjustments for the FTL (Flash Translation Layer) and MTD (Memory Technology Device) subsystems, primarily to:
Impact
Enables FTL/MTD subsystems to support non-traditional storage devices (RRAM/MRAM) that do not require erase operations, expanding the applicable scenario of the system.
Unifies the return value judgment standard of the MTD erase interface, avoiding potential errors caused by inconsistent return values; adds pre-check of the erase interface to prevent invalid operations.
Testing
We have actually tested RRAM/MRAM devices, confirming that no errors are reported when accessing them via the FTL interface, and the write/read functions work normally as expected.