[PATCH v2 0/2] dt-bindings: mtd: partitions: Export special values
Miquel Raynal
miquel.raynal at bootlin.com
Fri Oct 27 05:11:22 PDT 2023
Hi Edward,
equu at openmail.cc wrote on Fri, 27 Oct 2023 17:46:08 +0800:
> There are special "offset" and "size" values defined and documented in
> linux/mtd/partitions.h:
>
> /* consume as much as possible, leaving size after the end of partition. */
> #define MTDPART_OFS_RETAIN (uint64_t)(-3)
>
> /* the partition will start at the next erase block. */
> #define MTDPART_OFS_NXTBLK (uint64_t)(-2)
>
> /* the partition will start where the previous one ended. */
> #define MTDPART_OFS_APPEND (uint64_t)(-1)
>
> (Though not explicitly, they are compared against variables in uint64_t
> in drivers/mtd/mtdpart.c, so they had better be considered as such.)
>
> /* the partition will extend to the end of the master MTD device. */
> #define MTDPART_SIZ_FULL (0)
>
> These special values could be used to define partitions automatically
> fitting to the size of the master MTD device at runtime.
>
> However, these values used not to be exported to dt-bindings, thus
> seldom used before, since they might have been only used in numeric form,
> such as "(-1) (-3)" for MTDPART_OFS_RETAIN.
>
> Now, they are exported in dt-bindings/mtd/partitions.h as 32-bit cell
> values, so 2-cell addressed should be defined to use special offset values,
> such as "MTDPART_OFS_SPECIAL MTDPART_OFS_RETAIN" for MTDPART_OFS_RETAIN in
> linux/mtd/partitions.h. An example is added to fixed-partitions.yaml.
>
> Edward Chow (2):
> dt-bindings: mtd: partitions: Export special values
> dt-bindings: mtd: partitions: Document special values
>
> .../mtd/partitions/fixed-partitions.yaml | 30 +++++++++++++++++++
> MAINTAINERS | 2 ++
> include/dt-bindings/mtd/partitions.h | 15 ++++++++++
> 3 files changed, 47 insertions(+)
> create mode 100644 include/dt-bindings/mtd/partitions.h
>
> --
> 2.42.0
I've expressed my feelings regarding this series in your v1 but it
feels like you are completely ignoring them. As a reminder, I am
opposed to exporting these flags. They are outdated, legacy, have
never been used in DT and were never meant to be.
Thanks, Miquèl
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